Next Article in Journal
Modelling across Multiple Scales to Design Biopolymer Membranes for Sustainable Gas Separations: 1—Atomistic Approach
Previous Article in Journal
Investigation on Properties of Raw and Alkali Treated Novel Cellulosic Root Fibres of Zea Mays for Polymeric Composites
Previous Article in Special Issue
New Self-Healing Metallosupramolecular Copolymers with a Complex of Cobalt Acrylate and 4′-Phenyl-2,2′:6′,2″-terpyridine
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Polymers
Volume 15
Issue 7
10.3390/polym15071803
polymers-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Cd(II)/Mn(II)/Co(II)/Ni(II)/Zn(II) Coordination Polymers Built from Dicarboxylic Acid/Tetracarboxylic Acid Ligands: Their Structural Diversity and Fluorescence Properties

by
Lu Liu
1,
Jian-Min Li
2,
Meng-Di Zhang
1,
Hui-Jie Wang
1,
Ying Li
1,
Zhen-Bei Zhang
1,
Zi-Fang Zhao
1,
Yu Xi
1,
Yuan-Yuan Huang
1,
Jie Xu
1,
Bo Zhang
1,
Jun Chen
1 and
Cheng-Xing Cui
1,*
1
School of Chemistry and Chemical Engineering, Henan Institute of Science and Technology, Xinxiang 453003, China
2
School of Resources and Environment, Henan Institute of Science and Technology, Xinxiang 453003, China
*
Author to whom correspondence should be addressed.
Polymers 2023, 15(7), 1803; https://doi.org/10.3390/polym15071803
Submission received: 29 January 2023 / Revised: 29 March 2023 / Accepted: 30 March 2023 / Published: 6 April 2023
(This article belongs to the Special Issue Coordination Polymers: Properties and Applications II)
Browse Figures
Versions Notes

Abstract

:
Six Cd(II)/Mn(II)/Co(II)/Ni(II)/Zn(II) coordination complexes are formulated as [Cd2(X2−)2(μ3-O)2/3]n (1), [Mn2(X2−)2(μ3-O)2/3]n (2), {[Co1.5(Y4−)0.5(4,4′-bpy)1.5(OH−)]·2H2O}n (3), {[Ni(X2−)(4,4′-bpy)(H2O)2]·4H2O}n (4), [Zn(m-bdc2−)(bebiyh)]n (5), and [Cd(5-tbia2−)(bebiyh)]n (6) (H2X = 3,3′-(2,3,5,6-tetramethyl-1,4-phenylene) dipropionic acid. H4Y = 2,2′-(2,3,5,6-tetramethyl-1,4-phenylene)bis(methylene) dimalonic acid, bebiyh = 1,6-bis(2-ethyl-1H-benzo[d]imidazol-1-yl)hexane, m-H2bdc = 1,3-benzenedicarboxylic acid, and 5-H2tbia = 5-(tert-butyl)isophthalic acid) were obtained by hydrothermal reactions and structurally characterized. Complexes 1 and 2 have a 6-connected 3D architecture and with several point symbols of (36·46·53). Complex 3 features a 5-connected 3D net structure with a point symbol of (5·69). Complex 4 possesses a 4-connected 2D net with a vertex symbol of (44·62). Complex 5 is a 3-connected 2D network with a point symbol of (63). Complex 6 is a (3,3)-connected 2D network with a point symbol of (63)2. In addition, complexes 1 and 4 present good photoluminescence behaviors. The electronic structures of 1 and 4 were investigated with the density functional theory (DFT) method to understand the photoluminescence behaviors.

1. Introduction

The research and development of materials play vital roles in the development of modern society [1,2,3,4]. As a new type of functional material, complexes’ structures are modifiable and thus have easy to modify functions [5,6,7]. In the field of materials chemistry, the complex has been a hot topic [8,9,10].
Structure determines performance. If you want to get the desired performance of the complex, you have to design it properly which is exactly what we have been trying to pursue [11,12,13]. Complexes are self-assembled by central metal ions or clusters (inorganic components) and organic ligands (organic components), so selecting appropriate metal ions and organic ligands can realize the design and construction of this material [14,15]. Among them, the variety of ligands is extremely large. The organic ligands with different configurations have an important influence on the synthesis and structure of complexes. In terms of the toughness of the ligand, ligands can be divided into rigid, flexible, or semirigid. Although the stability of the complex constructed by rigid ligands is good, rigid ligands cannot twist at will, which makes the structure of the complex monotonous. Although more complex, novel, and exotic sturctures with varied configurations can be obtained using flexible ligands, complex structures synthesized by the ligands are difficult to control. To our satisfaction, semirigid ligands have the characteristics of both rigid and flexible ligands.
To date, many polycarboxylic acid ligands have been employed to construct complexes due to the abundant coordination patterns of carboxylic acids [16,17,18,19,20,21,22]. Carboxylic acids have the following advantages: firstly, the O atom on the carboxylic acid group has a strong electron-donating ability and it is easy to coordinate with metal ions. Secondly, the coordination modes of carboxylic groups are flexible and varied. There are roughly three modes: single tooth, chelate, and bridge. When coordinating with more than one metal, the three types of double, three, and four teeth are displayed. In addition, the different orientations of coordination bonds between metal ions and O atoms can be expressed as cis–cis, cis–anti, and anti–anti patterns. The structural diversity of the coordination patterns of carboxylic acids is impressive. Thirdly, carboxyl groups are completely or partially deprotonated, rendering them hydrogen bond acceptors or hydrogen bond donors. In this way, hydrogen bonds can be formed with more electronegative atoms such as O, N, and F, thus contributing to the formation of a supramolecular structure. Fourthly, the conjugation property of the aromatic ring is conducive to electron transfer. Therefore, semirigid polycarboxylate ligands are our first choice followed by rigid ligands. In addition, the mixing strategy of the polycarboxylic acid and N-donor ligand is also an effective method in the synthesis of multi-dimensional structures [23,24,25,26,27,28].
In view of this, the semirigid 3,3′-(2,3,5,6-tetramethyl-1,4-phenylene)dipropionic acid (H2X), 2,2′-(2,3,5,6-tetramethyl-1,4-phenylene)bis(methylene)dimalonic acid (H4Y), rigid 1,3-benzenedicarboxylic acid (m-H2bdc), and 5-(tert-butyl)isophthalic acid) (5-H2tbia) are selected as the primary ligand in this paper (Scheme 1). When 4,4′-bipyridine (4,4′-bpy) is present or not present, Cd(II) salt/Mn(II) salt/Co(II) salt/Ni(II) salt/Zn(II) salt reacts with H2X/H4Y/m-H2bdc/5-H2tbia to prepare six complexes: [Cd2(X2−)2(μ3-O)2/3]n (1), [Mn2(X2−)2(μ3-O)2/3]n (2), {[Co1.5(Y4−)0.5(4,4′-bpy)1.5(OH−)]·2H2O}n (3), {[Ni(X2−)(4,4′-bpy)(H2O)2]·4H2O}n (4), [Zn(m-bdc2−)(bebiyh)]n (5), and [Cd(5-tbia2−)(bebiyh)]n (6). We discuss the crystal structures of 1–6 and investigate the fluorescence properties of 1 and 4.

2. Materials and Methods

All reagents and solvents were purchased commercially except for H2X and H4Y [29]. In the region of 400–4000 cm−1, FT-IR spectra were tested on an FTIR-7600 spectrophotometer. The C, H, and N content was recorded on a FLASH EA 1112 elemental analyzer. The luminescence properties were studied using a Cary Eclipse fluorescence spectrophotometer.

2.1. Synthesis

Synthesis of [Cd2(X2−)2(μ3-O)2/3]n (1). A hybrid of Cd(NO3)2·4H2O (0.0308 g), H2X (0.0138 g), DMF(4 mL), and H2O (2 mL) was placed in a 25 mL reactor. It was heated at 100 °C for three days. It was then cooled to produce a colorless crystal 1. The yield is 36% (based on Cd). Anal. Calcd for C96H120Cd6O26 (%): C, 48.76, and H, 5.11. Found: C, 48.77, and H, 5.14. IR (KBr, cm−1): 3448(m), 2987(w), 1600(vs), 1428(m), 1319(w), 1226(vw), 1178(m), 1029(w), 1002(w), 946(w), 889(w), 786(w), 763(vw), 607(w), and 474(w).
Synthesis of [Mn2(X2−)2(μ3-O)2/3]n (2). A hybrid of MnCl2·4H2O (0.0297 g), H2X (0.0138 g), DMF (3 mL), EtOH (3 mL), and H2O (2 mL) was placed in a 25 mL reactor. It was also heated at 100 °C for three days. It was then cooled to produce a colorless crystal 2. The yield is 25% (based on Mn). Anal. Calcd for C96H120Mn6O26 (%): C, 57.09, and H, 5.99. Found: C, 57.12, and H, 5.97. IR (KBr, cm−1): 3417(s), 2983(vw), 1706(vw), 1616(s), 1488(w), 1440(w), 1398(s), 1322(s), 1261(w), 1222(w), 1170(w), 1002(w), 939(w), 835(w), 759(w), 713(vw), 611(s), and 485(s).
Synthesis of {[Co1.5(Y4−)0.5(4,4′-bpy)1.5(OH−)]·2H2O}n (3). A hybrid of Co(NO3)2·6H2O (0.0291 g), H4Y (0.0180 g), 4,4′-bpy (0.0156 g), CH3CN (6 mL), and H2O (2 mL) was placed in a 25 mL reactor. It was heated at 95 °C for four days. It was then cooled to produce a purple rod crystal 3. The yield is 10% (based on Co). Anal. Calcd for C48H54Co3N6O14 (%), C, 51.67; H, 4.88; and N, 7.53. Found: C, 51.64; H, 4.90; and N, 7.49.
Synthesis of {[Ni(X2−)(4,4′-bpy)(H2O)2]·4H2O}n (4). A hybrid of Ni(NO3)2·6H2O (0.0436 g), H2X (0.0138 g), 4,4′-bpy (0.0156 g), NaOH (0.008 g), and H2O (8 mL) was placed in a 25 mL reactor. It was heated at 130 °C for three days. It was then cooled to produce a green strip crystal 4. The yield is 16% (based on Ni). Anal. Calcd for C26H40NiN2O10 (%), C, 52.10; H, 6.72; and N, 4.67. Found: C, 52.13; H, 6.70; and N, 4.64.
Synthesis of [Zn(m-bdc2−)(bebiyh)]n (5). Zn(Ac)2·2H2O (0.2 mmol), bebiyh (0.1 mmol), m-H2bdc (0.2 mmol), NaOH (0.4 mmol), and H2O (8 mL) were mixed and heated in a 25-mL steel vessel at 120 °C for 3 days. After cooling the mixture, colorless crystals were obtained at a 12% yield (based on Zn).
Synthesis of [Cd(5-tbia2−)(bebiyh)]n (6). Cd(NO3)2·4H2O (0.2 mmol), bebiyh (0.1 mmol), 5-H2tbia (0.2 mmol), NaOH (0.4 mmol), and H2O (8 mL) were mixed and heated in a 25-mL steel vessel at 170 °C for 3 days. After cooling the mixture, crystals of 6 were obtained at an 11% yield (based on Cd).

2.2. X-ray Crystallography

Crystallographic data for 1–6 were collected using an Xcalibur Eos Gemini CCD diffractometer (Mo-Kα, λ = 0.71073 Å). Absorption corrections were applied by using a multi-scan program. The data were corrected for Lorentz and polarization effects. Structures were solved by immediate methods and refined with a full-matrix least-squares technique based on F2 using the ShelXL software package [30]. Then, all of the non-hydrogen atoms were refined anisotropically. The hydrogen atoms of ligands were assigned at perfect positions capitalizing on a riding model and then they were refined isotropically [30]. Crystallographic crystal data and structure refinement details for 1–6 are summarized in Table S1, while selected bond lengths and bond angles for 1–6 are listed in Table S2.

3. Results and Discussion

3.1. Crystal Structure Description of Complexes 1–6

3.1.1. Crystal Structures of [Cd2(X2−)2(μ3-O)2/3]n (1) and [Mn2(X2−)2(μ3-O)2/3]n (2)

Crystals 1 and 2 are isostructural. To be concise, only the structure of 1 is described in detail. The coordination environment of the Mn(II) ions and their correlation structure diagram in crystal 2 is presented in Figure S1. The asymmetric unit of 1 is composed of two Cd(II) atoms, two X2−, and 2/3 μ3-oxygen atoms. Each Cd1(II) atom has a hexagonal configuration formed by five carboxyl O atoms (O1, O2, O4, O5, and O5A) from five X2− anions and one O3 atom from μ3-O. Cd1-O bond length is between 2.190(3) and 2.436(6) Å (Figure 2a). Each Cd2(II) atom has a hexagonal configuration formed by five carboxyl O atoms (O6B, O7, O8B, O10, and O10A) from five X2− anions and one O9 atom from μ3-O. The Cd2-O bond length is between 2.210(6) and 2.451(6) Å. The O–Cd–O bond angles were in the range of 77.0(2)–169.3(2)°. In 2, the Mn1(II) atom and Mn2(II) atom both adopt a six-coordinated configuration, respectively. The Mn1-O bond length is between 2.116(4) and 2.321(4) Å and the Mn2-O bond length is between 2.121(4) and 2.281(4) Å. The O–Mn–O bond angles were in the range of 77.27(15)–172.91(18)°.
In 1, the ligand X2− exhibits a coordination pattern (Figure 1a). In this pattern, two carboxyl groups appear as μ2-η1:η1 and μ3-η1:η2, respectively, bridged with five Cd(II) ions. Based on this connection pattern, Cd1 and symmetrically related Cd1 atoms are bridged together by three carboxyl oxygen atoms and a μ3-O to produce a three-nucleated [Cd3O4] unit (SBU-A). The Cd2 atom and the symmetrically related Cd2 atom are also joined together by three carboxyl oxygen atoms and a μ3-O bridge to produce a three-nucleated [Cd3O4] unit (SBU-B). SBU-A and SBU-B are interchangeably connected by carboxyl oxygen atoms of X2−, resulting in a 1D chain structure (Figure 2b). The 1D chain forms a 3D structure under the extension of X2− (Figure 2c).
Polymers 15 01803 g001 550
Figure 1. Coordination patterns of acids in complexes. (a) The coordination pattern of X2− in 1. (b) The coordination pattern of X2− in 3. (c) The coordination pattern of X2− in 4.
Figure 1. Coordination patterns of acids in complexes. (a) The coordination pattern of X2− in 1. (b) The coordination pattern of X2− in 3. (c) The coordination pattern of X2− in 4.
Polymers 15 01803 g001
Topologically, the [CdO] unit can be considered as a 6-connected node, which is connected to six equivalent nodes through six X2− ligands. Each X2− links two [CdO] units, so the X2− can be simplified as links. Accordingly, the whole structure of 1 is related to a 6-connected network with a Schläfli symbol of (36·46·53) topology (Figure 2d).
Polymers 15 01803 g002 550
Figure 2. (a) Surrounding environment map of Cd(II) in complex 1, symmetric opcode: A = 1 − y, x − y, z; B = x, y, 1 + z. (b) Cd(II)/X2− 1D chain. (c) The 3D structure diagram of complex 1. (d) Schematic view of the 3D topology network for 1.
Figure 2. (a) Surrounding environment map of Cd(II) in complex 1, symmetric opcode: A = 1 − y, x − y, z; B = x, y, 1 + z. (b) Cd(II)/X2− 1D chain. (c) The 3D structure diagram of complex 1. (d) Schematic view of the 3D topology network for 1.
Polymers 15 01803 g002

3.1.2. Crystal Structures of {[Co1.5(Y4−)0.5(4,4′-bpy)1.5(OH−)]·2H2O}n (3)

The asymmetric unit of 3 is composed of one and a half Co(II) atoms, half a Y4− anion, one and a half 4,4′-bpy, a coordinated OH−, and two dissociative H2O molecules. Each Co1(II) atom has a hexagonal configuration formed by four carboxyl O atoms (O2, O3A, and O4A) from four Y4− anions, one O1 atom from coordinated H2O molecules, and two N atoms (N1 and N3) from two separate 4,4′-bpy (Figure 3a). The Co1-O bond length is between 2.054(5) and 2.159(6) Å. The Co1-N bond length is between 2.170(6) and 2.184(6) Å. Each Co2(II) atom has a hexagonal configuration formed by four carboxyl O atoms (O6, O7, O6B, and O7B) and two N atoms (N2 and N2B). The Co2-O bond length is between 2.105(6) and 2.112(7) Å. The Co2-N bond lengths are all 2.176(7) Å. The O/N–Co–O/N bond angles were in the range of 81.6(2)–180.0(4)°.
In 3, the 1D chain (Co(II)/4,4′-bpy chain) along the b-axis is also built by 4,4′-bpy ligands and Co(II) ions (Co1, symmetrically related Cd1 atoms and Co2) with a Co…Co distance of 11.4397 Å and 11.4606 Å (Figure 3b). The ligand Y4− exhibits a coordination pattern (Figure 1b). In this pattern, four carboxyl groups appear as μ4-η1:η2:η1:η2, bridged with four Co(II) ions. Based on this connection pattern, Co1 and symmetrically related Cd1 atoms are bridged together by four carboxyl oxygen atoms to form a 2D layer (Figure 3c). The combination of 1D chains of Co(II)/4,4′-bpy and 2D Co(II)/Y4− generates the 3D structure of 3 (Figure 3d).
As depicted in Figure 3e, topological analysis is performed on 3. If the binuclear unit constituted by Co1 and symmetrically related Cd1 atoms is taken as a 5-connector, the Y4− and Cd2 atoms can be defined as linkers, and the 3D framework of 3 can be classified as a 5-connected net with point symbol of (5·69).

3.1.3. Crystal Structures of {[Ni(X2−)(4,4′-bpy)(H2O)2]·4H2O}n (4)

The asymmetric unit of 4 is composed of a Ni(II) atom, an X2− anion, 4,4′-bpy, a coordinated H2O molecule, and four free H2O molecules. Each Ni(II) atom has a hexagonal configuration formed by two carboxyl O atoms (O1 and O1A) from two X2− anions, two N atoms (N1, N2B) from two 4,4′-bpy ligands, and two O atoms (O3, O3A) from two coordinated H2O molecules (Figure 4a). The length of the Ni-O bond varies from 2.085(3)-2.086(3)/2.086(4) Å, while the length of the Ni-N1 bond is 2.117(5) Å, and the length of the Ni-N2B bond is 2.129(5) Å. The O/N–Ni–O/N bond angles were in the range of 81.6(2)–180.0(4)°.
X2− adopts a trans-configuration and its two carboxyl groups adopt a single-tooth coordination mode (Figure 1c). The dihedral angle of the two pyridine rings of 4,4′-bpy is close to 90°. In 4, 4,4′-bpy connects adjacent Ni(II) ions along an a-axis to generate a 1D straight chain structure (Figure 4b). Whereas, X2− connects adjacent Ni(II) ions to generate a 1D wave-like chain structure along an a-axis (Figure 4c). Both 1D Ni(II)/4,4′-bpy chains and 1D Ni(II)/X2− chains are alternately connected to form 2D layer structures (Figure 4d).
To further demonstrate the overall 2D structure of 4, we can consider each Ni(II) as a 4-connecting node which is linked to four equivalent nodes through two X2− anions and two 4,4′-bpy. X2− and 4,4′-bpy are simplified as linear linkers separately. The whole structure of 4 can be simplified to a 4-connected net with a vertex symbol of (44·62) (Figure 4e).

3.1.4. Crystal Structure of [Zn(m-bdc2−)(bebiyh)]n (5)

Each asymmetric unit of 5 consists of one Zn(II) ion, one bebiyh, and one m-bdc2−. The Zn(II) ion adopts a four-coordinated configuration ligated by two nitrogen atoms (N1 and N3) from two bebiyh as well as two oxygen atoms (O2, O3A) from two m-bdc2− anions (Figure S2a). The structural index parameter (τ4) [31,32] is close to 1.0, indicating that the geometry around Zn(II) can be described as a tetrahedral geometry. The Zn−O bond length is 1.980(8) Å and the Zn−N bond length is the range of 2.081(8)–2.093(10) Å. Bebiyh adopts a symmetric trans-conformation with Ndonor…N−Csp3…Csp3 torsion angles of 102.601° and 114.332°. In 5, the two bebiyh act as a bidentate mode to joint two adjacent Zn(II) ions to form a 26-membered ring with a Zn···Zn separation of 11.3803 Å (Figure S2b). The m-bdc2− adopted a μ2-η1:η1 mode. Each m-bdc2− bridges two Zn(II) ions to generate a 1D Zn(II)/m-bdc2− chain along the c-axis with a Zn···Zn separation of 10.4882 Å (Figure S2c). The combination of the 1D Zn(II)/m-bdc2− chain and the 26-membered ring produces the 2D structure of 5 (Figure S2d) by sharing zinc ions.
To further demonstrate the overall 2D structure of 5, we can consider each Zn(II) as a 3-connecting node which is linked to three equivalent nodes through two m-bdc2− anions and one 26-membered ring. The m-bdc2− and 26-membered ring are simplified as linear linkers separately. The whole structure of 5 can be simplified to a 3-connected net with a vertex symbol of (63) (Figure S2e).

3.1.5. Crystal Structure of [Cd(5-tbia2−)(bebiyh)]n (6)

Each asymmetric unit of 6 consists of one Cd(II) ion, one bebiyh, and one 5-tbia2−. The Cd1 ion adopts a five-coordinated configuration ligated by one nitrogen atom (N1) from two bebiyh as well as three oxygen atoms (O1A, O2A, and O3) from two 5-tbia2− (Figure S3a). The structural index parameter (τ5) [31,32] is close to 0.1, indicating that the geometry around Cd1 can be described as a square pyramidal structure. The Cd1−O/N bond length is in the range of 2.191(6)–2.581(7) Å. Whereas, the O/N–Cd1–O/N bond angles were in the range of 53.2(2)–144.3(3)°. The Cd2 ion adopts a six-coordinated configuration ligated by two nitrogen atoms (N5 and N7) from two bebiyh as well as four oxygen atoms (O5, O6, O7, and O8) from two 5-tbia (Figure S3a). The Cd2−O/N bond length is in the range of 2.218(6)–2.607(6) Å. Whereas, O/N–Cd2–O/N bond angles were in the range of 53.8(2)–150.6(2)°.
In 6, bebiyh adopts a symmetric trans-conformation with the Ndonor…N−Csp3…Csp3 torsion angle of 85.233° and 91.397°. The bebiyh act in bidentate mode to join two adjacent Cd(II) ions to form a 1D Cd(II)/bebiyh chain along the a-axis with a Cd···Cd separation of 8.9479 and 13.1222 Å (Figure S3b). The 5-tbia2− adopted a μ2-η1:η1 mode. Each 5-tbia bridges two Cd(II) ions to generate a 1D Cd(II)/5-tbia chain with a Cd…Cd separation of 8.9479 and 9.3580 Å (Figure S3c). The combination of the 1D Cd(II)/bebiyh chain and Cd(II)/5-tbia2− chain by sharing cadmium ions produces the 2D structure of 6 (Figure S3d).
To further demonstrate the overall 2D structure of 6, we can consider each Cd (II) (Cd1(II) and Cd2(II)) as a 3-connecting node. The 5-tbia2− and bebiyh are simplified as linear linkers separately. The whole structure of 6 can be simplified to a (3,3)-connected net with a vertex symbol of (63)2 (Figure S3e).

3.2. Photoluminescence Properties

We investigated the fluorescence spectrum of complexes 1 and 4 and the free ligand H2X (Figure S4). H2X shows an emission band at 300 nm (λex = 282 nm). The emission band of 4,4′-bpy is 428 nm (λex = 350 nm) [33]. The fluorescence emission peaks were observed at 301 nm for complex 1 (λex = 281 nm) and 306 nm for complex 4 (λex = 265 nm), respectively. The emission peak of 1 is similar to that of H2X, which may be mainly attributed to the endoligand emission of H2X. The emission band of complex 4 is red-shifted by 6 nm, thus corresponding to the emission band of H2X. As for 4,4′-bpy, the emission band of complex 4 is blue-shifted by 122 nm. This may be due to coordination with metal ions. To better understand the photoluminescent properties of complexes 1 and 4, we further performed theoretical investigations on their model systems as shown in Figure 5. We optimized the four geometries at the theoretical level of M06L/6-31G(d,p) under a vacuum, where the SDD effective core potential was applied for the metallic elements. We further calculated the excited properties with the time dependent density function theory (TDDFT) method [34], where the option of nstates for TDDFT was set as 10 [35]. The calculated Cd2-O bond length is 2.558 Å, which is similar to the experimental results (between 2.210(6) and 2.451(6) Å). The calculated emission wavelength of complex 1 is 278 nm and the oscillator strength is as large as 0.228, which is consistent with the experimental results. Moreover, the relevant orbitals for the excited process are HOMO, LUMO+7, and LUMO+8, with corresponding energies of −4.45 eV, 0.37 eV, and 0.53 eV, respectively (Figure 5a). The luminescent processes are related to the frontier orbitals including HOMO, LUMO+3, and LUMO+4. For complex 4, as shown in Figure 5b, the calculated luminescent properties are both relevant to the metal center, which is indicative of their crucial roles. As shown in Figure 5c,d where we gave the calculated emission spectrum of complexes 1 and 4, the oscillator strength of 1 is arguably larger than 4. This indicates that the emission of 4 is weaker than 1, which is in line with the experimental observations.

4. Conclusions

Six new Cd(II)/Mn(II)/Co(II)/Ni(II)/Zn(II)-containing coordination complexes based on the dicarboxylic acid/tetracarboxylic acid ligands were synthesized. Complexes 1, 2, and 3 feature several 3D net structures. Complex 4, 5, 6 possesses a 2D layer structure, severally. The structure of the ligand has an important effect on the configuration of the complex, leading to the formation of different beautiful topologies. The theoretical calculation results indicate that the luminescence could be mainly related to the metal center for complexes 1 and 4, while the oscillator strength of 1 is larger than 4.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/polym15071803/s1. Figure S1: (a) Surrounding environment map of Mn(II) in complex 2, symmetric opcode: A = x, y, 1 + z; B = −y, x − y, 1 + z; C = 0.33333 − x + y, 0.66667 − x, − 0.33333 + z; (b) Mn(II)/X2− 1D chain; and (c) the 3D structure diagram of complex 2. Figure S2: (a) Coordination environment diagram around the Zn(II) center in 5; (b) the 26-membered rings constructed by two bebiyh ligands and two Zn atoms; (c) 1D Zn/m-H2bdc chain; (d) the 2D layer structure of 5; and (e) schematic view of the 2D topology network for 5. Figure S3: (a) coordination environment diagram around the Cd(II) center in 6; (b) 1D Cd/bebiyh chain; (c) 1D Cd/5-tbia chain; (d) 2D layer structure of 6; and (e) schematic view of the 2D topology network for 6. Figure S4: Photoluminescent emission spectrum of the free H2X ligand, complexes 1 and 4. Figure S5: Experimental (red) and simulated (black) PXRD patterns of complex 1 (a), 2 (b), and 4 (c). Table S1: Crystallographic data and structure refinement details for complex 1–6a,b. Table S2: Table S2 Selected Bond Lengths (Å) and Bond Angles (deg) for 1–6a.

Author Contributions

Conceptualization, J.-M.L. and Y.L.; methodology, Z.-B.Z.; software, H.-J.W.; validation, B.Z.; formal analysis, M.-D.Z.; investigation, Y.X.; resources, J.X.; data curation, Y.-Y.H.; writing-original draft preparation, L.L.; writing—review and editing, L.L.; visualization, Z.-F.Z.; supervision, J.C.; project administration, C.-X.C.; funding acquisition, L.L. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Key Scientific Research Project of Colleges and Universities in Henan Province (No. 23A150039), the Key Scientific and Technological Project of Henan Province (No. 222102320259, 222102240001, 212102210304, and 222102310117), the Henan University of Science and Technology innovation and entrepreneurship training program for college students (No. 2022CX095), and the Training Plan for University’s Young Backbone Teachers of Henan Province (No. 2019GGJS170).

Institutional Review Board Statement

Not applicable.

Data Availability Statement

Crystallographic data for 1–6 were deposited at the Cambridge Crystallographic Data Centre with CCDC reference numbers 2232253–2232256 and 2237514–2237515.

Conflicts of Interest

The authors declare no conflict of interest.

Sample Availability

Sample of the compound is available from the authors.

References

  1. Annamalai, J.; Murugan, P.; Ganapathy, D.; Nallaswamy, D.; Atchudan, R.; Arya, S.; Khosla, A.; Barathi, S.; Sundramoorthy, A.K. Synthesis of various dimensional metal organic frameworks (MOFs) and their hybrid composites for emerging applications-A review. Chemosphere 2022, 298, 134184. [Google Scholar] [CrossRef]
  2. Yuan, S.; Feng, L.; Wang, K.C.; Pang, J.D.; Bosch, M.; Lollar, C.; Sun, Y.J.; Qin, J.S.; Yang, X.Y.; Zhang, P. Stable Metal-Organic Frameworks: Design, Synthesis, and Applications. Adv. Mater. 2018, 30, 1704303. [Google Scholar] [CrossRef] [Green Version]
  3. Ghazvini, M.F.; Vahedi, M.; Nobar, S.N.; Sabouri, F. Investigation of the MOF adsorbents and the gas adsorptive separation mechanisms. J. Environ. Chem. Eng. 2021, 9, 104790. [Google Scholar] [CrossRef]
  4. Mu, X.Y.; Wang, W.K.; Sun, C.C.; Wang, J.L.; Wang, C.B.; Knez, M. Recent Progress on Conductive Metal-Organic Framework Films. Adv. Mater. Interfaces 2021, 8, 2002151. [Google Scholar] [CrossRef]
  5. Qin, Y.T.; Li, Z.X.; Duan, Y.L.; Guo, J.; Zhao, M.T.; Tang, Z.Y. Nanostructural engineering of metal-organic frameworks: Construction strategies and catalytic applications. Matter 2022, 5, 3260–3310. [Google Scholar] [CrossRef]
  6. Zheng, Y.S.; Sun, F.Z.; Han, X.; Xu, J.L.; Bu, X.H. Recent Progress in 2D Metal-Organic Frameworks for Optical Applications. Adv. Opt. Mater. 2020, 8, 2000110. [Google Scholar] [CrossRef]
  7. Sumida, K.; Rogow, D.L.; Mason, J.A.; McDonald, T.M.; Bloch, E.D.; Herm, Z.R.; Bae, T.H.; Long, J.R. Carbon Dioxide Capture in Metal-Organic Frameworks. Chem. Rev. 2012, 112, 724–781. [Google Scholar] [CrossRef] [PubMed]
  8. Gándara, F.; Uribe-Romo, F.J.; Britt, D.K.; Furukawa, H.; Lei, L.; Cheng, R.; Duan, X.F.; O’Keeffe, M.; Yaghi, O.M. Porous, Conductive Metal-Triazolates and Their Structural Elucidation by the Charge-Flipping Method. Chem.-Eur. J. 2012, 18, 10595–10601. [Google Scholar] [CrossRef] [PubMed]
  9. Jain, P.; Ramachandran, V.; Clark, R.J.; Zhou, H.D.; Toby, B.H.; Dalal, N.S.; Kroto, H.W.; Cheetham, A.K. Multiferroic Behavior Associated with an Order-Disorder Hydrogen Bonding Transition in Metal-Organic Frameworks (MOFs) with the Perovskite ABX3 Architecture. J. Am. Chem. Soc. 2009, 131, 13625–13627. [Google Scholar] [CrossRef] [PubMed]
  10. Kurmoo, M. Magnetic metal-organic frameworks. Chem. Soc. Rev. 2009, 38, 1353–1379. [Google Scholar] [CrossRef]
  11. Song, F.; Wang, C.; Lin, W. A chiral metal-organic framework for sequential asymmetric catalysis. Chem. Commun. 2011, 47, 8256–8258. [Google Scholar] [CrossRef] [PubMed]
  12. Cui, Y.J.; Yue, Y.F.; Qian, G.D.; Chen, B.L. Luminescent Functional Metal-Organic Frameworks. Chem. Rev. 2012, 112, 1126–1162. [Google Scholar] [CrossRef] [PubMed]
  13. Lan, A.; Li, K.; Wu, H.; Olson, D.H.; Emge, T.J.; Ki, W.; Hong, M.C. A Luminescent Microporous Metal-Organic Framework for the Fast and Reversible Detection of High Explosives. Angew. Chem. Int. Edit. 2009, 48, 2334–2338. [Google Scholar] [CrossRef] [PubMed]
  14. Kreno, L.E.; Leong, K.; Farha, O.K.; Allendorf, M.; Duyne, R.P.V.; Hupp, J.T. Metal-Organic Framework Materials as Chemical Sensors. Chem. Rev. 2012, 112, 1105–1125. [Google Scholar] [CrossRef]
  15. Xie, Z.; Ma, L.; de Krafft, K.E.; Jin, A.; Lin, W.B. Porous Phosphorescent Coordination Polymers for Oxygen Sensing. J. Am. Chem. Soc. 2010, 132, 922–923. [Google Scholar] [CrossRef]
  16. You, Z.X.; Xiao, Y.; Guan, Q.L.; Xing, Y.H.; Bai, F.Y.; Xu, F. Cage Bismuth Metal-Organic Framework Materials Based on a Flexible Triazine-Polycarboxylic Acid: Subgram Synthesis, Application for Sensing, and White Light Tuning. Inorg. Chem. 2022, 61, 13893–13914. [Google Scholar] [CrossRef]
  17. Zhang, N.; Sun, L.X.; Bai, F.Y.; Xing, Y.H. Thorium-Organic Framework Constructed with a Semirigid Triazine Hexacarboxylic Acid Ligand: Unique Structure with Thorium Oxide Wheel Clusters and Iodine Adsorption Behavior. Inorg. Chem. 2020, 59, 3964–3973. [Google Scholar] [CrossRef]
  18. Peng, Y.W.; Wu, R.J.; Liu, M.; Yao, S.; Geng, A.F.; Zhang, Z.M. Nitrogen Coordination To Dramatically Enhance the Stability of In-MOF for Selectively Capturing CO2 from a CO2/N2 Mixture. Cryst. Growth Des. 2019, 19, 1322–1328. [Google Scholar] [CrossRef]
  19. Zhan, C.; Zou, C.; Kong, G.Q.; Wu, C.D. Four Honeycomb Metal-Organic Frameworks with a Flexible Tripodal Polyaromatic Acid. Cryst. Growth Des. 2013, 13, 1429–1437. [Google Scholar] [CrossRef]
  20. Qin, J.S.; Du, D.Y.; Li, M.; Lian, X.Z.; Dong, L.Z.; Bosch, M.; Su, Z.M.; Zhang, Q.; Li, S.L.; Lan, Y.Q.; et al. Derivation and Decoration of Nets with Trigonal-Prismatic Nodes: A Unique Route to Reticular Synthesis of Metal-Organic Frameworks. J. Am. Chem. Soc. 2016, 138, 5299–5307. [Google Scholar] [CrossRef]
  21. Zhang, X.P.; Zhou, J.M.; Shi, W.; Zhang, Z.J.; Cheng, P. Two cadmium(II) coordination polymers constructed by carboxylate and pyridine mixed ligands: Synthesis, structure and luminescent properties. CrystEngComm 2013, 15, 9738–9744. [Google Scholar] [CrossRef]
  22. Gu, J.Z.; Cai, Y.; Wen, M.; Shi, Z.F.; Kirillov, A.M. A new series of Cd(II) metal-organic architectures driven by soft ether-bridged tricarboxylate spacers: Synthesis, structural and topological versatility, and photocatalytic properties. Dalton Trans. 2018, 47, 14327–14339. [Google Scholar] [CrossRef] [PubMed]
  23. Mao, S.S.; Lin, Y.H.; Li, X.Y.; Wang, H. Highly Luminescent Metal-Organic Frameworks Based on Binary Chromophoric Ligands Derived from Tetraphenylethylene. Cryst. Growth Des. 2022, 22, 5791–5795. [Google Scholar] [CrossRef]
  24. Fan, C.B.; Huang, G.M.; Zhiyong Xing, Z.Y.; Wang, J.L.; Pang, Y.Q.; Huang, Q.P.; Huang, S.F.; Zong, Z.; Guo, F. Three multi-responsive luminescent Zn-CPs for the detection of antibiotics/cations/anions in aqueous media. CrystEngComm 2023, 25, 593–600. [Google Scholar] [CrossRef]
  25. Liu, L.; Lv, X.F.; Zhang, L.; Guo, L.A.; Wu, J.; Hou, H.W.; Fan, Y.T. Mn(II) coordination polymers assembled from 8 or 9-connected trinuclear secondary building units: Topology analysis and research of magnetic properties. CrystEngComm 2014, 16, 8736–8746. [Google Scholar] [CrossRef]
  26. Liang, L.L.; Liu, C.S.; Zong, Z.H.; Zhang, M.L.; Zhang, B.Y.; Cao, R.; Wang, Z.H.; Pang, M.M.; Li, Y.J.; Tao, Z.L. Syntheses, Crystal Structures and Antimicrobial Activities of Two Coordination Polymers Based on Bisbenzimidazole Ligands and V-Shaped Dicarboxylates. Chin. J. Inorg. Chem. 2018, 34, 1365–1372. [Google Scholar]
  27. Li, Y.; Zou, X.Z.; Gu, J.Z.; Cheng, X.L. Syntheses, Crystal Structures and Magnetic Properties of Two Copper(II) and Manganese(II) Coordination Compounds Constructed from Biphenyl Tricarboxylic Acid. Chin. J. Inorg. Chem. 2018, 34, 1159–1165. [Google Scholar]
  28. Hu, J.S.; Shang, Y.J.; Yao, X.Q.; Qin, L.; Li, Y.Z.; Guo, Z.J.; Zheng, H.G.; Xue, Z.L. Syntheses, Structures, and Photochemical Properties of Six New Metal-Organic Frameworks Based on Aromatic Dicarboxylate Acids and V-Shaped Imidazole Ligands. Cryst. Growth Des. 2010, 10, 4135–4142. [Google Scholar] [CrossRef]
  29. Wijesekera, T.P.; David, S.; Paine, J.B., III; James, B.R.; Dolphin, D. Durene-capped porphyrins: Synthesis and characterization. Can. J. Chem. 1988, 66, 2063–2071. [Google Scholar] [CrossRef]
  30. Sheldrick, G.M. A short history of SHELX. Acta Crystallogr. Sect. A Found. Crystallogr. 2008, 64, 112–122. [Google Scholar] [CrossRef] [Green Version]
  31. Song, X.Z.; Song, S.Y.; Qin, C.; Su, S.Q.; Zhao, S.N.; Zhu, M.; Hao, Z.M.; Zhang, H.J. Syntheses, Structures, and Photoluminescent Properties of Coordination Polymers Based on 1,4-Bis(imidazol-l-yl-methyl)benzene and Various Aromatic Dicarboxylic Acids. Cryst. Growth Des. 2012, 12, 253–263. [Google Scholar] [CrossRef]
  32. Yang, L.; Powell, D.R.; Houser, R.P. Structural variation in copper(I) complexes with pyridylmethylamide ligands: Structural analysis with a new four-coordinate geometry index, τ4. Dalton Trans. 2007, 9, 955–964. [Google Scholar] [CrossRef] [PubMed]
  33. Zhang, S.Q.; Jiang, F.L.; Wu, M.Y.; Jie Ma, J.; Yang Bu, Y.; Hong, M.C. Assembly of Discrete One-, Two-, and Three-Dimensional Zn(II) Complexes Containing Semirigid V-Shaped Tricarboxylate Ligands. Cryst. Growth Des. 2012, 12, 1452–1463. [Google Scholar] [CrossRef]
  34. Zhao, Z.X.; Zhao, G.L.; Lu, B.X.; Zhang, H.H.; Li, G.S.; Wang, L.F.; Cui, C.X. Tuning novel Cd(II) topology networks through choosing three neutral and zwitterionic N/O-donor ligands: Synthesis, structures, and fluorescence. J. Phys. Org. Chem. 2020, 34, e4150. [Google Scholar] [CrossRef]
  35. Furche, F.; Ahlrichs, R. Adiabatic time-dependent density functional methods for excited state properties. J. Chem. Phys. 2002, 117, 7433–7447. [Google Scholar] [CrossRef]
Polymers 15 01803 sch001 550
Scheme 1. The organic ligand in this paper.
Scheme 1. The organic ligand in this paper.
Polymers 15 01803 sch001
Polymers 15 01803 g003 550
Figure 3. (a) Surrounding environment map of Co(II) in complex 3, symmetric opcode: A = 0.5 − x, 0.5 + y, 0.5 − z; B = 1 − x, −y, −z. (b) Co(II)/4,4′-bpy 1D chain. (c) Co(II)/Y4− 2D layer. (d) The 3D structure diagram of complex 3. (e) Schematic view of the 3D topology network for 3.
Figure 3. (a) Surrounding environment map of Co(II) in complex 3, symmetric opcode: A = 0.5 − x, 0.5 + y, 0.5 − z; B = 1 − x, −y, −z. (b) Co(II)/4,4′-bpy 1D chain. (c) Co(II)/Y4− 2D layer. (d) The 3D structure diagram of complex 3. (e) Schematic view of the 3D topology network for 3.
Polymers 15 01803 g003
Polymers 15 01803 g004 550
Figure 4. (a) Surrounding environment map of Ni(II) in complex 4, symmetric opcode: A = x, 0.5 − y, z; B = 1 + x, y, 1 + z. (b) Ni(II)/X2− 1D chain. (c) Ni(II)/4,4′-bpy 1D chain. (d) The 2D structure diagram of complex 4. (e) Schematic view of the 2D topology network for 4.
Figure 4. (a) Surrounding environment map of Ni(II) in complex 4, symmetric opcode: A = x, 0.5 − y, z; B = 1 + x, y, 1 + z. (b) Ni(II)/X2− 1D chain. (c) Ni(II)/4,4′-bpy 1D chain. (d) The 2D structure diagram of complex 4. (e) Schematic view of the 2D topology network for 4.
Polymers 15 01803 g004
Polymers 15 01803 g005 550
Figure 5. The calculated excitation of complexes 1 (a) and 4 (b) and the calculated emission spectrum of 1 (c) and 4 (d) at the theoretical level of TD−M06L/6−31G(d,p), where the SDD effective core potential was applied for the metallic elements.
Figure 5. The calculated excitation of complexes 1 (a) and 4 (b) and the calculated emission spectrum of 1 (c) and 4 (d) at the theoretical level of TD−M06L/6−31G(d,p), where the SDD effective core potential was applied for the metallic elements.
Polymers 15 01803 g005
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Liu, L.; Li, J.-M.; Zhang, M.-D.; Wang, H.-J.; Li, Y.; Zhang, Z.-B.; Zhao, Z.-F.; Xi, Y.; Huang, Y.-Y.; Xu, J.; et al. Cd(II)/Mn(II)/Co(II)/Ni(II)/Zn(II) Coordination Polymers Built from Dicarboxylic Acid/Tetracarboxylic Acid Ligands: Their Structural Diversity and Fluorescence Properties. Polymers 2023, 15, 1803. https://doi.org/10.3390/polym15071803

AMA Style

Liu L, Li J-M, Zhang M-D, Wang H-J, Li Y, Zhang Z-B, Zhao Z-F, Xi Y, Huang Y-Y, Xu J, et al. Cd(II)/Mn(II)/Co(II)/Ni(II)/Zn(II) Coordination Polymers Built from Dicarboxylic Acid/Tetracarboxylic Acid Ligands: Their Structural Diversity and Fluorescence Properties. Polymers. 2023; 15(7):1803. https://doi.org/10.3390/polym15071803

Chicago/Turabian Style

Liu, Lu, Jian-Min Li, Meng-Di Zhang, Hui-Jie Wang, Ying Li, Zhen-Bei Zhang, Zi-Fang Zhao, Yu Xi, Yuan-Yuan Huang, Jie Xu, and et al. 2023. "Cd(II)/Mn(II)/Co(II)/Ni(II)/Zn(II) Coordination Polymers Built from Dicarboxylic Acid/Tetracarboxylic Acid Ligands: Their Structural Diversity and Fluorescence Properties" Polymers 15, no. 7: 1803. https://doi.org/10.3390/polym15071803

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop