Coordination Chemistry: Current Developments and Future Perspectives — A Themed Issue in Honor of Professor Spyros P. Perlepes on the Occasion of His 70th Birthday

A special issue of Chemistry (ISSN 2624-8549). This special issue belongs to the section "Inorganic and Solid State Chemistry".

Deadline for manuscript submissions: closed (30 April 2023) | Viewed by 28765

Special Issue Editors

Foundation for Research and Technology, Institute of Chemical Engineering Sciences (ICE-HT/FORTH), Department of Chemistry, University of Patras, GR-26504 Patras, Greece
Interests: molecular inorganic chemistry; spin crossover phenomenon; raman spectroscopy; metal organic frameworks
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Guest Editor
Department of Science and High Technology (DiSAT), University of Insubria, 22100 Como, Italy
Interests: coordination chemistry; non-covalent interactions; biological inorganic chemistry; heterogeneous catalysis; nanomaterials

Special Issue Information

Dear Colleagues,

Spyros P. Perlepes is an Emeritus Professor in the Chemistry Department of the University of Patras, Patras, Greece. He has been an active researcher in inorganic chemistry for the last 40 years or so, with many remarkable achievements in the chemistry of metal complexes. His research interests cover a variety of topics ranging from the development of new synthetic methods and the systematic study of the reactivity of coordinated ligands, to the preparation of homo- and heterometallic complexes with interesting properties (optical, magnetic, catalytic) and the chemistry of non-dangerous 5f metals.

The title of this Special Issue is “Coordination Chemistry: Current Developments and Future Perspectives”. Its central goal is to show that Coordination Chemistry is a vibrant and highly interdisciplinary field with a brilliant future. The aim of this issue is to provide readers of Chemistry with a compilation of high-quality research papers and reviews in all areas of Coordination Chemistry. These include (but are not limited to) synthetic aspects, design of ligands, the chemistry of coordination clusters, coordination polymers and Metal–Organic Frameworks (MOFs), Bioinorganic and Medicinal Inorganic Chemistry, molecular materials based on complexes, solution chemistry and mechanistic studies, stoichiometric or catalytic organic transformations by metal complexes, physical and spectroscopic properties of coordination compounds, improvement of existing or development of new methods for the detailed study of metal complexes, their applications in life and other fields of science, and prognosis for the future. Both experimental and theoretical studies are welcome.

Dr. Zoi G. Lada
Dr. Konstantis Konidaris
Guest Editors

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Keywords

  • applications of coordination compounds
  • biological inorganic chemistry
  • coordination chemistry
  • coordination clusters
  • coordination polymers
  • molecular inorganic chemistry
  • metal- organic frameworks
  • properties of coordination complexes (magnetic, optical, catalytic,…)
  • spectroscopy of coordination compounds
  • theoretical inorganic chemistry

Published Papers (18 papers)

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Research

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11 pages, 12967 KiB  
Article
Blue-Emitting 2D- and 3D-Zinc Coordination Polymers Based on Schiff-Base Amino Acid Ligands
by Rodavgi Karakousi, Pinelopi A. Tsami, Maria-Areti I. Spanoudaki, Scott J. Dalgarno, Vassileios C. Papadimitriou and Constantinos J. Milios
Chemistry 2023, 5(3), 1770-1780; https://doi.org/10.3390/chemistry5030121 - 09 Aug 2023
Viewed by 1072
Abstract
The solvothermal reaction of Zn(NO3)2·4H2O, 1-OH-2-naphthaldehyde, and 2-methylalanine (mAla) in MeOH leads to the formation of complex {[ZnL1]}2n (1) (H2L1 = the Schiff-base resulting from the reaction [...] Read more.
The solvothermal reaction of Zn(NO3)2·4H2O, 1-OH-2-naphthaldehyde, and 2-methylalanine (mAla) in MeOH leads to the formation of complex {[ZnL1]}2n (1) (H2L1 = the Schiff-base resulting from the reaction of 1-OH-2-naphthaldehyde and mAla) in good yields. The structure of the neutral species, as determined by single-crystal crystallography, describes a two-dimensional coordination polymer, with repeating {Zn2} units bridged by syn, anti-carboxylate groups of the Schiff-base ligands. Repeating the same reaction using glycine (gly) instead of mAla leads to the formation of complex {[ZnL2]·0.33MeOH}3n (2.0.33MeOH) (H2L2 = the Schiff-base resulting from the reaction of 1-OH-2-naphthaldehyde and gly), again in good yields. Complex 2 describes a three-dimensional coordination polymer based on {Zn2} building blocks, arranged by anti, anti-carboxylate groups in a 3D motif. Complexes 1 and 2 were found to strongly emit at ~435 nm (λexc = 317 nm) both in solution and solid state, with complex 2 displaying a slightly longer lifetime of τav = 2.45 ns vs. τav = 2.02 ns for 1. Full article
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15 pages, 3777 KiB  
Article
Rare Nuclearities and Unprecedented Structural Motifs in Manganese Cluster Chemistry from the Combined Use of Di-2-Pyridyl Ketone with Selected Diols
by Katerina Skordi, Dimitris I. Alexandropoulos, Adeline D. Fournet, Nikos Panagiotou, Eleni E. Moushi, Constantina Papatriantafyllopoulou, George Christou and Anastasios J. Tasiopoulos
Chemistry 2023, 5(3), 1681-1695; https://doi.org/10.3390/chemistry5030115 - 01 Aug 2023
Viewed by 1028
Abstract
The combined use of di-2-pyridyl ketone ((py)2CO) with various diols in Mn cluster chemistry has afforded five new compounds, namely, [Mn11O2(OH)2{(py)2CO2}5(pd)(MeCO2)3(N3)3(NO [...] Read more.
The combined use of di-2-pyridyl ketone ((py)2CO) with various diols in Mn cluster chemistry has afforded five new compounds, namely, [Mn11O2(OH)2{(py)2CO2}5(pd)(MeCO2)3(N3)3(NO3)2(DMF)4](NO3)∙2DMF∙H2O (1∙2DMF∙H2O), [Mn11O2(OH)2{(py)2CO2}5(mpd)(MeCO2)3(N3)3(NO3)2(DMF)4](NO3) (2), [Mn12O4(OH)2{(py)2CO2}4(mpd)2(Me3CCO2)4(NO3)4(H2O)6](NO3)2∙2MeCN (3∙2MeCN), [Mn4(OMe)2{(py)2C(OMe)O}2(2-hp)2(NO3)2(DMF)2] (4), and [Mn7{(py)2CO2}4(2-hp)4(NO3)2(DMF)2](ClO4)∙DMF (5∙DMF) ((py)2CO22− and (py)2C(OMe)O = gem-diol and hemiketal derivatives of di-2-pyridyl ketone, pdH2 = 1,3-propanediol, mpdH2 = 2-metly-1,3-propanediol, 2-hpH2 = 2-(hydroxymethyl)phenol). Complexes 1 and 2 are isostructural, possessing an asymmetric [MnIII5MnII64-O)(μ3-O)(μ3-OH)(μ-OH)(μ3-OR)2(μ-OR)10(μ-N3)]8+ core. Compound 3 is based on a multilayer [MnIII8MnII44-O)23-O)23-OH)2(μ-OR)12]10+ core, while complex 4 comprises a defective dicubane core. The crystal structure of 5 reveals that it is based on an unusual non-planar [MnIII5MnII2(μ-OR)12]7+ core with a serpentine-like topology. Direct current (dc) magnetic susceptibility studies revealed the presence of dominant antiferromagnetic exchange interactions in complex 3, while ferromagnetic coupling between the Mn ions was detected in the case of compound 5. Fitting of the magnetic data for complex 4 revealed weak antiferromagnetic interactions along the peripheral MnII∙∙∙MnIII ions (Jwb = −0.33 (1) cm−1) and ferromagnetic interactions between the central MnIII∙∙∙MnIII ions (Jbb = 6.28 (1) cm−1). Full article
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22 pages, 6161 KiB  
Article
Structural and Magnetic Analysis of a Family of Structurally Related Iron(III)-Oxo Clusters of Metal Nuclearity Fe8, Fe12Ca4, and Fe12La4
by Alok P. Singh, ChristiAnna L. Brantley, Kenneth Hong Kit Lee, Khalil A. Abboud, Juan E. Peralta and George Christou
Chemistry 2023, 5(3), 1599-1620; https://doi.org/10.3390/chemistry5030110 - 24 Jul 2023
Viewed by 1414
Abstract
The synthesis, crystal structure, and magnetic characterization are reported for three new structurally related iron(III) compounds (NHEt3)[Fe8O5(OH)5(O2PPh2)10] (1), [Fe12 Ca4O10(O2CPh) [...] Read more.
The synthesis, crystal structure, and magnetic characterization are reported for three new structurally related iron(III) compounds (NHEt3)[Fe8O5(OH)5(O2PPh2)10] (1), [Fe12 Ca4O10(O2CPh)10(hmp)4] (2), and [Fe12La4O10(OH)4(tbb)24] (3), where hmpH is 2-(hydroxymethyl)pyridine and tbbH is 4-tBu-benzoic acid. 1 was obtained from the reaction of Fe(NO3)3·9H2O, diphenylphosphinic acid (Ph2PO2H), and NEt3 in a 1:4:16 molar ratio in MeCN at 50 °C; 2 was obtained from the reaction of [Fe3O(O2CPh)6(H2O)3](NO3), Ca(NO3)2, and NEt3 in a 1:1:4:2 ratio at 130 °C; and 3 was obtained from the reaction of Fe(NO3)3·9H2O, La(NO3)3·6H2O, 4-tBu-benzoic acid, and NEt3 in a 1:1:4:4 ratio in PhCN at 140 °C. The core of 1 consists of two {Fe43-O)2}8+ butterfly units stacked on top of each other and bridged by O2− and HO ions. The cores of 2 and 3 also contain two stacked butterfly units, plus four additional Fe atoms, two at each end, and four M atoms (M = Ca2+ (2); La3+ (3)) on the sides. Variable-temperature (T) and solid-state dc and ac magnetization (M) data collected in the 1.8–300 K range revealed that 1 has an S = 0 ground state, 2 has a χMT value at low T consistent with the central Fe8 in a local S = 0 ground state and the two Fe3+ ions in each end-pair to be non-interacting, whereas 3 has a χMT value at low T consistent with these end-pairs each being ferromagnetically coupled with S = 5 ground states, plus intermolecular ferromagnetic interactions. These conclusions were reached from complementing the experimental studies with the calculation of the various Fe2 pairwise Jij exchange couplings by DFT computations and by using a magnetostructural correlation (MSC) for polynuclear Fe3+/O complexes, as well as a structural analysis of the intermolecular contacts in the crystal packing of 3. Full article
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10 pages, 1736 KiB  
Communication
Synthesis of the Bipyridine-Type Ligand 3-(2-Pyridyl)-5,6-diphenyl-1,2,4-triazine and Structural Elucidation of Its Cu(I) and Ag(I) Complexes
by Antonios Hatzidimitriou, Antonios Stamatiou, Dimitrios Tzimopoulos and Pericles D. Akrivos
Chemistry 2023, 5(3), 1508-1517; https://doi.org/10.3390/chemistry5030103 - 05 Jul 2023
Viewed by 1084
Abstract
The synthesis of a substituted diimine with a bipydirine-type backbone, (3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine, L) and its coordination towards Cu(I) and Ag(I) is studied in the presence of diphosphine ligand bis(diphenylphosphino)methane, dppm. The metal complexes are characterized by IR, 1H, and 13C NMR and [...] Read more.
The synthesis of a substituted diimine with a bipydirine-type backbone, (3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine, L) and its coordination towards Cu(I) and Ag(I) is studied in the presence of diphosphine ligand bis(diphenylphosphino)methane, dppm. The metal complexes are characterized by IR, 1H, and 13C NMR and single crystal X ray diffraction studies. They are dinuclear, as they are held by diphosphine bridges between the tetrahedral metal centers, forming eight-membered ring with the participation of the bridging diphosphinomethane ligands. Within each ring, the planar orientations of M2P2 and of all four P atoms are realized. Solid state excitation spectra are dominated by metal-to-ligand charge transfer bands (MLCT), while geometry relaxation permits only low-intensity emission for the copper compound. Full article
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12 pages, 4026 KiB  
Article
The Anion Impact on Dimensionality of Cadmium(II) Complexes with Nicotinamide
by Željka Soldin, Boris-Marko Kukovec, Milica Kovačić, Marijana Đaković and Zora Popović
Chemistry 2023, 5(2), 1357-1368; https://doi.org/10.3390/chemistry5020092 - 01 Jun 2023
Viewed by 1357
Abstract
Three novel cadmium(II) coordination compounds, the dimeric [Cd(CH3COO)2(nia)2]2 (1), the polymeric {[Cd(nia)4](ClO4)2}n (2), and the monomeric [Cd(H2O)3(nia)3](ClO4) [...] Read more.
Three novel cadmium(II) coordination compounds, the dimeric [Cd(CH3COO)2(nia)2]2 (1), the polymeric {[Cd(nia)4](ClO4)2}n (2), and the monomeric [Cd(H2O)3(nia)3](ClO4)2·nia (3), were prepared in the reactions of the nicotinamide (pyridine-3-carboxamide, nia) with the corresponding cadmium(II) salts. All prepared compounds were characterized by elemental analyses, FT-IR spectroscopy, TGA/DTA, and single crystal X-ray analysis. The impact of anions (acetate, perchlorate) and solvent used on the dimensionality of cadmium(II) complexes and the cadmium(II) coordination environment was investigated. The bridging capabilities of acetate ions enabled the formation of dimers in the crystal structure of 1. It was shown that the dimensionality of perchlorate complexes depends on the solvent used. The coordination polymer 2 is isolated from an ethanol solution, while monomeric compound 3 was obtained by using a water/ethanol mixture as a solvent. The pentagonal-bipyramidal coordination of cadmium(II) was found in the presence of chelating and bridging acetate ions in 1. In the presence of non-coordinating perchlorate anions in 2 and 3, the coordination geometry of cadmium(II) is found to be octahedral. The supramolecular amide-amide homosynthon R22(8) was preserved in the hydrogen-bonded frameworks of all three compounds. Full article
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14 pages, 3804 KiB  
Article
Using Imidazolium in the Construction of Hybrid 2D and 3D Lead Bromide Pseudoperovskites
by Gonzalo García-Espejo, Konstantis F. Konidaris, Antonietta Guagliardi and Norberto Masciocchi
Chemistry 2023, 5(2), 1329-1342; https://doi.org/10.3390/chemistry5020090 - 26 May 2023
Viewed by 1202
Abstract
The field of hybrid organic–inorganic perovskite materials continues to attract the interest of the scientific community due to their fascinating properties and the plethora of promising applications in photovoltaic and optoelectronic devices. To enhance the efficiency and stability of perovskite-based devices, it is [...] Read more.
The field of hybrid organic–inorganic perovskite materials continues to attract the interest of the scientific community due to their fascinating properties and the plethora of promising applications in photovoltaic and optoelectronic devices. To enhance the efficiency and stability of perovskite-based devices, it is essential to discover novel compounds but also to investigate their various physicochemical, structural, and thermal properties. In this work, we report the synthesis and structural characterization of two novel hybrid lead bromide perovskites, combining the imidazolium cation (IMI) with methylammonium (MA) or formamidinium (FA) cations. The isolated polycrystalline powders were studied with X-ray powder diffraction (XPRD) and were formulated as (IMI)(MA)Pb2Br6, a 3D structure consisting of dimers of face-sharing octahedra linked in corner-sharing mode, and (IMI)(FA)PbBr4, a 2D (110) oriented layer structure with zig-zag corner-sharing octahedra. The thermal stability of (IMI)(MA)Pb2Br6 and (IMI)(FA)PbBr4 was investigated with thermogravimetric (TG) and differential scanning calorimetry (DSC) experiments which showed that both compounds are chemically stable (at least) up to 250 °C. Variable-temperature X-ray diffractometric (VT-XRD) studies of (IMI)(FA)PbBr4 highlighted a structural modification occurring above 100 °C, that is a phase transformation from triclinic to orthorhombic, via an elusive monoclinic phase. Full article
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10 pages, 2311 KiB  
Communication
A Missing Nuclearity in the Co(III)/Ln(III)/2-Pyridyladoxime Chemistry: Tetranuclear Compounds Using the “Assisted Self-Assembly” Approach (Ln = Rare Earth Metals)
by Zoi G. Lada, Eugenia Katsoulakou, Christina D. Polyzou, Catherine P. Raptopoulou and Vassilis Psycharis
Chemistry 2023, 5(2), 996-1005; https://doi.org/10.3390/chemistry5020068 - 27 Apr 2023
Viewed by 1280
Abstract
By employing the HSAB principle and the “assisted self-assembly” approach and using 2-pyridylaldoximate (pao) as the primary ligand and pivalate (piv) as the ancillary co-ligand, tetranuclear [CoIII2LnIII2(NO3)4(pao)4(piv) [...] Read more.
By employing the HSAB principle and the “assisted self-assembly” approach and using 2-pyridylaldoximate (pao) as the primary ligand and pivalate (piv) as the ancillary co-ligand, tetranuclear [CoIII2LnIII2(NO3)4(pao)4(piv)4] complex polynuclear compounds were isolated (Ln = Dy, Gd, Tb, Pr, Y). The structure of the Dy(III) complex was determined via single-crystal X-ray crystallography, revealing a metal topology of two {CoIIIDyIII2} triangles that shared a common DyIIIDyIII edge. Microanalytical, PXRD (for the two first members)d and spectroscopic (IR, EDX) data for all complexes provided strong evidence that the complexes were isostructural. The nuclearity and metal topology of the crystallographically characterized [CoIII2LnIII2(NO3)4(pao)4(piv)4] are new in the previously investigated CoIII/LnIII/pao chemistry emphasizing utility of the “assisted self-assembly” approach. Full article
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9 pages, 5196 KiB  
Communication
Single-Ion Magnetism in a Three-Dimensional Thiocyanate-Bridged Dysprosium(III) Framework
by Qingyun Wan, Mirosław Arczyński, Masanori Wakizaka, Shraddha Gupta, Nobuto Funakoshi and Masahiro Yamashita
Chemistry 2023, 5(2), 987-995; https://doi.org/10.3390/chemistry5020067 - 26 Apr 2023
Cited by 2 | Viewed by 1357
Abstract
New three-dimensional (3D) lanthanide framework compounds supported by bridging thiocyanate ligand and K+ cations, K4[Ln(NCS)4(H2O)4](NCS)3(H2O)2(1: Ln = Dy, 2: Ln = Tb, 3: Ln = Gd) have [...] Read more.
New three-dimensional (3D) lanthanide framework compounds supported by bridging thiocyanate ligand and K+ cations, K4[Ln(NCS)4(H2O)4](NCS)3(H2O)2(1: Ln = Dy, 2: Ln = Tb, 3: Ln = Gd) have been synthesized. A single-crystal X-ray diffraction study showed that all three compounds were isostructural and crystallized in the I 2/a space group. The K+ ion form 2D layers with thiocyanates which are further linked by [Ln(NCS)4(H2O)4]- complexes and additional thiocyanate ions to generate an interesting 3D framework structure. Compound 1 shows slow magnetic relaxation behavior under a zero direct current (DC) field, indicating that 1 behaves as a single-ion magnet (SIM). As estimated from AC magnetic measurements, the effective energy barrier for spin reversal in 1 was Ueff = 42 cm–1. Slow relaxation of magnetization under a small external DC field was also detected for 2 and 3 at 1.8 K. Full article
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10 pages, 2143 KiB  
Article
Nature Inspired Manganese(III)-Calcium Complexes: Towards Synthetic Models for the WOC of PSII
by Joaquin Bonelli Blasco, Sara Mauri Querol, Kevin Consuegra Naranjo and E. Carolina Sañudo
Chemistry 2023, 5(2), 703-712; https://doi.org/10.3390/chemistry5020049 - 23 Mar 2023
Viewed by 1178
Abstract
For some time, the presence of high oxidation state Mn ions and Ca(II) in the active center of Photosystem II has been known. However, coordination complexes that combine both Mn(III) and Ca(II) have been difficult to obtain, with only a handful of examples [...] Read more.
For some time, the presence of high oxidation state Mn ions and Ca(II) in the active center of Photosystem II has been known. However, coordination complexes that combine both Mn(III) and Ca(II) have been difficult to obtain, with only a handful of examples reported. In this paper we report the synthesis of two new Mn(III)-Ca(II) complexes, 1 [Pr2NH2]3[Mn6CaO2(OH)(OMe)3(SALO)6 (SALOH)3] and 2 [Mn18Ca6O12(OH)6(MeO)12(PhCOO)18(MeOH)6]. The complexes have been characterized by single-crystal X-ray diffraction to establish the oxidation state of manganese. The use of salicylato ligands with tert-butyl substituents leads to effective encapsulation of a Ca(II) ion in a cavity that has both hydrophobic and hydrophilic regions, mimicking the enzyme environment. Full article
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14 pages, 1977 KiB  
Article
Crystal Engineering of Conglomerates: Dilution of Racemate-Forming Fe(II) and Ni(II) Congeners into Conglomerate-Forming [Zn(bpy)3](PF6)2
by Ugo Serdan, Lucas Robin, Mathieu Marchivie, Mathieu Gonidec, Patrick Rosa, Elen Duverger-Nédellec, Emilie Pouget, Philippe Sainctavit, Marie-Anne Arrio, Amélie Juhin, Andrei Rogalev, Fabrice Wilhelm and Elizabeth A. Hillard
Chemistry 2023, 5(1), 255-268; https://doi.org/10.3390/chemistry5010020 - 15 Feb 2023
Viewed by 1770
Abstract
Conglomerate formation, where enantiomers within a racemic mixture self-segregate upon crystallization, is an advantageous property for obtaining chirally pure crystals and allows large-scale chiral resolution. However, the prevalence of conglomerates is low and difficult to predict. In this report, we describe our attempts [...] Read more.
Conglomerate formation, where enantiomers within a racemic mixture self-segregate upon crystallization, is an advantageous property for obtaining chirally pure crystals and allows large-scale chiral resolution. However, the prevalence of conglomerates is low and difficult to predict. In this report, we describe our attempts to engineer conglomerates from racemate-forming compounds by integrating them into a conglomerate-forming matrix. In this regard, we found that Ni(II) and Fe(II) form molecular alloys with Zn(II) in [MxZn(1−x)(bpy)3](PF6)2 (where bpy = 2,2′-bipyridyl). Powder X-ray Diffraction (PXRD) and Energy-Dispersive X-ray spectroscopy (EDX) evidenced conglomerate crystallization with Ni(II) concentrations up to about 25%, while it was observed only for much lower concentrations of Fe(II). This can be attributed to the ability of [Ni(bpy)3](PF6)2 to access a metastable conglomerate phase, while no such phase has been detected in [Fe(bpy)3](PF6)2. Furthermore, the chiral phase appears to be favored in fast-growing precipitates, while the racemic phase is favored in slow re-crystallizations for both Ni(II) and Fe(II) molecular alloys. X-ray natural circular dichroism (XNCD) measurements on [Ni0.13Zn0.87(bpy)3](PF6)2 demonstrate the chirality of the nickel molecules within the zinc molecular matrix. Full article
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14 pages, 5811 KiB  
Article
Trinuclear and Cyclometallated Organometallic Dinuclear Pt-Pyrazolato Complexes: A Combined Experimental and Theoretical Study
by Zhichun Shi, Fengyu Li, Hong Zhao, Indranil Chakraborty, Zhongfang Chen and Raphael G. Raptis
Chemistry 2023, 5(1), 187-200; https://doi.org/10.3390/chemistry5010016 - 29 Jan 2023
Viewed by 1987
Abstract
Two differently substituted pyrazole ligands have been investigated with regard to the topology of their Pt complexes: upon deprotonation, two mononuclear 1:2 PtII-pyrazole complexes—one of the sterically unhindered 4-Me-pzH and one of the bulky 3,5-tBu-pzH (pzH = pyrazole)—yield the [...] Read more.
Two differently substituted pyrazole ligands have been investigated with regard to the topology of their Pt complexes: upon deprotonation, two mononuclear 1:2 PtII-pyrazole complexes—one of the sterically unhindered 4-Me-pzH and one of the bulky 3,5-tBu-pzH (pzH = pyrazole)—yield the corresponding 1:2 PtII-pyrazolato species; the former a triangular, trinuclear metallacycle (1), and the latter a dinuclear, half-lantern species (2) formed via the unprecedented cyclometallation of a butyl group. Stoichiometric oxidation of the colorless PtII2 complex produces the deep-blue, metal–metal bonded PtIII2 analog (3) with a rarely encountered unsymmetrical coordination across the Pt-Pt bond. All three complexes have been characterized by single crystal X-ray structure determination, 1H-NMR, IR, and UV-vis-NIR spectroscopic methods. The XPS spectra of the PtII2 and PtIII2 species are also reported. Density functional theory calculations were carried out to investigate the electronic structure, spectroscopic properties, and chemical bonding of the new complexes. The calculated natural population analysis charges and Wiberg bonding indices indicate a weak σ-interaction in the case of 2 and a formal Pt-Pt single bond in 3. Full article
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8 pages, 1706 KiB  
Communication
Noncentrosymmetric Supramolecular Hydrogen-Bonded Assemblies Based on Achiral Pyrazine-Bridged Zinc(II) Coordination Polymers with Pyrazinedione Derivatives
by Ko Yoneda, Ken Kanazashi, Hitoshi Kumagai, Ryuta Ishikawa and Satoshi Kawata
Chemistry 2023, 5(1), 179-186; https://doi.org/10.3390/chemistry5010015 - 26 Jan 2023
Viewed by 1195
Abstract
Reaction of M(OAc)2·xH2O (M, x = Zn, 2 and Co, 4), 1,4-dihydro-5,6-dicyano-2,3-pyrazinedione (H2CN2pyzdione), and pyrazine (pyz) affords two compounds of the same molecular formula {[M(H2O)6][M(CN2pyzdione)2(pyz)]·6H [...] Read more.
Reaction of M(OAc)2·xH2O (M, x = Zn, 2 and Co, 4), 1,4-dihydro-5,6-dicyano-2,3-pyrazinedione (H2CN2pyzdione), and pyrazine (pyz) affords two compounds of the same molecular formula {[M(H2O)6][M(CN2pyzdione)2(pyz)]·6H2O}n (M = Zn for 1 and Co for 2) in which discrete units of [M(H2O)6]2+ are linked to one-dimensional chains of [M(CN2pyzdione)2(pyz)]2– via multiple O–H···O hydrogen-bonding interactions and M2+-bound H2O molecules in [M(H2O)6]2+ also serve as linkers of hydrogen-bonded interstitial H2O molecules. Remarkably, 1 crystallizes in the monoclinic crystal system, the similar crystal system and unit cell parameters as 2, but with a space group distinct from 1 and 2, i.e., 1 is the noncentrosymmetric space group C2, whereas 2 is the centrosymmetric space group C2/m. This polar structure for 1 is induced by the presence of alternating arrangements of distinguishable two axial Zn–N bonds within [Zn(CN2pyzdione)2(pyz)]2– chains. Indeed, solid-state circular dichroism spectra of 1 exhibit significant Cotton effects, as evidenced by the polar space group C2. Moreover, these Cotton effects show clear temperature-dependence depending on contents of H2O molecules of 1. Full article
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13 pages, 2498 KiB  
Article
A New Unnatural Amino Acid Derived from the Modification of 4′-(p-tolyl)-2,2′:6′,2″-terpyridine and Its Mixed-Ligand Complexes with Ruthenium: Synthesis, Characterization, and Photophysical Properties
by Konstantinos Ypsilantis, Antonia Garypidou, Andreas Gikas, Alexandros Kiapekos, John C. Plakatouras and Achilleas Garoufis
Chemistry 2023, 5(1), 151-163; https://doi.org/10.3390/chemistry5010012 - 15 Jan 2023
Viewed by 1671
Abstract
The modification of the methyl group of 4′-(p-tolyl)-2,2′:6′,2″-terpyridine produced the novel unnatural amino acid 3-(4-([2,2′:6′,2″-terpyridin]-4′-yl)phenyl)-2-aminopropanoic acid (phet). Mononuclear heteroleptic ruthenium complexes of the general formulae [Ru(L1)(L2)](PF6)2 (L1 = 2-acetylamino-2-(4-[2,2′:6′,2″]terpyridine-4′-yl-benzyl)-malonic acid diethyl ester, (phem), 3-(4-([2,2′:6′,2″-terpyridin]-4′-yl)phenyl)-2-aminopropanoic acid, [...] Read more.
The modification of the methyl group of 4′-(p-tolyl)-2,2′:6′,2″-terpyridine produced the novel unnatural amino acid 3-(4-([2,2′:6′,2″-terpyridin]-4′-yl)phenyl)-2-aminopropanoic acid (phet). Mononuclear heteroleptic ruthenium complexes of the general formulae [Ru(L1)(L2)](PF6)2 (L1 = 2-acetylamino-2-(4-[2,2′:6′,2″]terpyridine-4′-yl-benzyl)-malonic acid diethyl ester, (phem), 3-(4-([2,2′:6′,2″-terpyridin]-4′-yl)phenyl)-2-aminopropanoic acid, (phet), and L2 = 2,2′:6′,2″-terpyridine (tpy), 4′-phenyl-2,2′:6′,2″-terpyridine (ptpy), 4′-(p-tolyl)-2,2′:6′,2″-terpyridine (mptpy)), as well as the homoleptic [Ru(phem)2](PF6)2 and [Ru(phet)2](PF6)2, were synthesized and characterized by means of NMR spectroscopic techniques, elemental analysis, and high-resolution mass spectrometry. The photophysical properties of the synthesized complexes were also studied. Full article
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12 pages, 1497 KiB  
Article
Synthesis, Structural, Magnetic and Computational Studies of a One-Dimensional Ferromagnetic Cu(II) Chain Assembled from a New Schiff Base Ligand
by Anne Worrell, Gabriele Delle Monache, Mark M. Turnbull, Jeremy M. Rawson, Theocharis C. Stamatatos and Melanie Pilkington
Chemistry 2023, 5(1), 85-96; https://doi.org/10.3390/chemistry5010007 - 07 Jan 2023
Viewed by 1919
Abstract
A new asymmetrically substituted ONOO Schiff base ligand N-(2′-hydroxy-1′-naphthylidene)-3-amino-2-naphthoic acid (nancH2) was prepared from the condensation of 2–hydroxy–1–naphthaldehyde and 3–amino–2–naphthoic acid. nancH2 reacts with Cu2(O2CMe)4·2H2O in the presence of [...] Read more.
A new asymmetrically substituted ONOO Schiff base ligand N-(2′-hydroxy-1′-naphthylidene)-3-amino-2-naphthoic acid (nancH2) was prepared from the condensation of 2–hydroxy–1–naphthaldehyde and 3–amino–2–naphthoic acid. nancH2 reacts with Cu2(O2CMe)4·2H2O in the presence of Gd(O2CMe)3·6H2O to afford a uniform one-dimensional homometallic chain, [CuII(nanc)]n (1). The structure of 1 was elucidated via single crystal X-ray diffraction studies, which revealed that the Cu(II) ions adopt distorted square planar geometries and are coordinated in a tridentate manner by an [ONO] donor set from one nanc2− ligand and an O of a bridging carboxylate group from a second ligand. The bridging carboxylato group of the nanc2− ligand adopts a syn, anti-η11:μ conformation linking neighboring Cu(II) ions, forming a 1D chain. The magnetic susceptibility of 1 follows Curie–Weiss law in the range 45–300 K (C = 0.474(1) emu K mol-1, θ = +7.9(3) K), consistent with ferromagnetic interactions between S = ½ Cu(II) ions with g = 2.248. Subsequently, the data fit well to the 1D quantum Heisenberg ferromagnetic (QHFM) chain model with g = 2.271, and J = +12.3 K. DFT calculations, implementing the broken symmetry approach, were also carried out on a model dimeric unit extracted from the polymeric chain structure. The calculated exchange coupling via the carboxylate bridge (J = +13.8 K) is consistent with the observed ferromagnetic exchange between neighbouring Cu(II) centres. Full article
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12 pages, 1376 KiB  
Article
Oxalamide Based Fe(II)-MOFs as Potential Electrode Modifiers for Glucose Detection
by Panagiotis Oikonomopoulos, Varvara Pagkali, Evangelia Kritikou, Anthi Panara, Marios G. Kostakis, Nicolaos S. Thomaidis, Thomais G. Tziotzi, Anastasios Economou, Christos Kokkinos and Giannis S. Papaefstathiou
Chemistry 2023, 5(1), 19-30; https://doi.org/10.3390/chemistry5010002 - 20 Dec 2022
Viewed by 1555
Abstract
In an attempt to expand the coordination chemistry of N,N′-bis(2,4-dicarboxyphenyl)-oxalamide (H6L) ligand, we isolated and structurally characterized two new Fe(II) Metal-Organic Frameworks (MOFs), namely [Fe2(H2L)(H2O)5] (3D-Fe-MOF) and [Fe(H4L)(H2 [...] Read more.
In an attempt to expand the coordination chemistry of N,N′-bis(2,4-dicarboxyphenyl)-oxalamide (H6L) ligand, we isolated and structurally characterized two new Fe(II) Metal-Organic Frameworks (MOFs), namely [Fe2(H2L)(H2O)5] (3D-Fe-MOF) and [Fe(H4L)(H2O)2]∙2H2O, (2D-Fe-MOF) by carefully adjusting the reaction conditions to achieve the optimal degree of deprotonation of the bridging ligand. Both MOFs were found stable in water, as evidenced by powder X-ray diffraction data and their ability to sorb glucose (GLU) from either an aqueous solution or artificial sweat was investigated only to show negligible sorption. A graphite paste sensor (GPE) using the 3D-Fe-MOF as a modifier was fabricated. The 3D-Fe-MOF modified GPE was assessed for non-enzymatic GLU detection in aqueous solution at pH 6 via differential pulse voltammetry and the preliminary results were discussed. Full article
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12 pages, 2991 KiB  
Article
Enhancing NO Uptake in Metal-Organic Frameworks via Linker Functionalization. A Multi-Scale Theoretical Study
by Charalampos G. Livas, Emmanuel Tylianakis and George E. Froudakis
Chemistry 2022, 4(4), 1300-1311; https://doi.org/10.3390/chemistry4040086 - 18 Oct 2022
Cited by 3 | Viewed by 1597
Abstract
In the present work, ab initio calculations and Monte Carlo simulations were combined to investigate the effect of linker functionalization on nitric oxide (NO)’s storage ability of metal–organic frameworks (MOFs). The binding energy (BE) of nitric oxide with a set of forty-two strategically [...] Read more.
In the present work, ab initio calculations and Monte Carlo simulations were combined to investigate the effect of linker functionalization on nitric oxide (NO)’s storage ability of metal–organic frameworks (MOFs). The binding energy (BE) of nitric oxide with a set of forty-two strategically selected, functionalized benzenes was investigated using Density Functional Theory calculations at the RI-DSD-BLYP/def2-TZVPP level of theory. It was found that most of the functional groups (FGs) increased the interaction strength compared to benzene. Phenyl hydrogen sulfate (–OSO3H) was the most promising among the set of ligands, with an enhancement of 150%. The organic linker of IRMOF-8 was modified with the three top-performing functional groups (–OSO3H, –OPO3H2, –SO3H). Their ability for NO adsorption was investigated using Grand Canonical Monte Carlo (GCMC) simulations at an ambient temperature and a wide pressure range. The results showed great enhancement in NO uptake constituting the above-mentioned FGs, suggesting them to be promising modification candidates in a plethora of porous materials. Full article
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12 pages, 3712 KiB  
Article
Enhancing of CO Uptake in Metal-Organic Frameworks by Linker Functionalization: A Multi-Scale Theoretical Study
by Charalampos G. Livas, Emmanuel Tylianakis and George E. Froudakis
Chemistry 2022, 4(2), 603-614; https://doi.org/10.3390/chemistry4020043 - 16 Jun 2022
Cited by 4 | Viewed by 1851
Abstract
In the present work, the interaction strength of Carbon Monoxide (CO) with a set of forty-two, strategically selected, functionalized benzenes was calculated. Our ab initio calculations at the MP2/6-311++G** level of theory reveal that phenyl hydrogen sulfate (-OSO3H) showed the highest [...] Read more.
In the present work, the interaction strength of Carbon Monoxide (CO) with a set of forty-two, strategically selected, functionalized benzenes was calculated. Our ab initio calculations at the MP2/6-311++G** level of theory reveal that phenyl hydrogen sulfate (-OSO3H) showed the highest interaction with CO (−19.5 kJ/mol), which was approximately three times stronger compared with the unfunctionalized benzene (−5.3 kJ/mol). Moreover, the three top-performing functional groups (-OSO3H, -OPO3H2, -SO3H) were selected to modify the organic linker of IRMOF-8 and test their ability to capture CO at 298 K for a wide pressure range. Our Grand Canonical Monte Carlo (GCMC) simulations showed a significant increase in the CO uptake in the functionalized MOFs compared with the parent IRMOF-8. It is distinctive that for the volumetric uptake, a 60× increase was observed at 1 bar and 2× was observed at 100 bar. The proposed functionalization strategy can be applied for improving the CO uptake performance not only in MOFs but also in various other porous materials. Full article
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Review

Jump to: Research

35 pages, 3684 KiB  
Review
Synthetic and Structural Chemistry of Uranyl-Amidoxime Complexes: Technological Implications
by Sokratis T. Tsantis, Maria Iliopoulou, Demetrios I. Tzimopoulos and Spyros P. Perlepes
Chemistry 2023, 5(2), 1419-1453; https://doi.org/10.3390/chemistry5020097 - 13 Jun 2023
Cited by 1 | Viewed by 2037
Abstract
Resource shortage is a major problem in our world. Nuclear energy is a green energy and because of this and its high energy density, it has been attracting more and more attention during the last few decades. Uranium is a valuable nuclear fuel [...] Read more.
Resource shortage is a major problem in our world. Nuclear energy is a green energy and because of this and its high energy density, it has been attracting more and more attention during the last few decades. Uranium is a valuable nuclear fuel used in the majority of nuclear power plants. More than one thousand times more uranium exists in the oceans, at very low concentrations, than is present in terrestrial ores. As the demand for nuclear power generation increases year-on-year, access to this reserve is of paramount importance for energy security. Water-insoluble polymeric materials functionalized with the amidoxime group are a technically feasible platform for extracting uranium, in the form of {UO2}2+, from seawater, which also contains various concentrations of other competing metal ions, including vanadium (V). An in-depth understanding of the coordination modes and binding strength of the amidoxime group with uranyl and other competing ions is a key parameter for improving extraction efficiency and selectivity. Very limited information on the complexation of {UO2}2+ with amidoximes was available before 2012. However, significant advances have been made during the last decade. This report reviews the solid-state coordination chemistry of the amidoxime group (alone or within ligands with other potential donor sites) with the uranyl ion, while sporadic attention on solution and theoretical studies is also given. Comparative studies with vanadium complexation are also briefly described. Eight different coordination modes of the neutral and singly deprotonated amidoxime groups have been identified in the structures of the uranyl complexes. Particular emphasis is given to describing the reactivity of the open-chain glutardiamidoxime, closed-ring glutarimidedioxime and closed-ring glutarimidoxioxime moieties, which are present as side chains on the sorbents, towards the uranyl moiety. The technological implications of some of the observed coordination modes are outlined. It is believed that X-ray crystallography of small uranyl-amidoxime molecules may help to build an understanding of the interactions of seawater uranyl with amidoxime-functionalized polymers and improve their recovery capacity and selectivity, leading to more efficient extractants. The challenges for scientists working on the structural elucidation of uranyl coordination complexes are also outlined. The review contains six sections and 95 references. Full article
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