Mononuclear zinc carboxylates [Zn(L)(2,2′-bpy)2](ClO 4)(nH2O) (1-4) (LH = 3-aminobenzoic acid (3-abaH) (1), salicylic acid (saH2) (2), 3,5-diisopropylsalicylic acid (dipsaH 2) (3), and 3-methyl-2-thiophenecarboxylic acid (3-Me-2-TCAH) (4)) and cadmium carboxylates [Cd(tipba)(2,2′-bpy)2](tipbaH) (5) (tipaH = 2,4,6-triisopropylbenzoic acid), [Cd(2,2′-bpy) 2(2-TCA)(ClO4)] (6) (2-TCAH = thiophene-2-carboxylic acid) and [{Cd(2,2′-bpy)2(3-Me-2-TCA)}{Cd(2,2′-bpy) 2(3-Me-2-TCA)(H2O)}](ClO4)2 (7) have been synthesized from the reaction of the metal precursor complex [M(OAc)(2,2′-bpy)2](ClO4)(H2O) (M = Zn and Cd) with the respective aromatic carboxylic acid in methanol at ambient conditions. Complexes 1-7 have been characterized with the aid of elemental analysis and FT-IR, UV-Vis, fluorescence, 1H NMR spectroscopic methods and further analyzed by single-crystal X-ray diffraction studies. The carboxylate groups show chelating and monodentate coordination behavior in these complexes. While the cadmium ion in 6 is heptacoordinated, the structure of 5 reveals a coordination number of eight with square antiprismatic geometry. Hydrogen bonding patterns in 1-4 and 7 result in a 1-D polymeric structure while 5 is a 2-D layer structure and 6 is a 3-D polymeric structure. © 2013 The Authors.

Palanisami N

Department of Chemistry

School of Advanced Sciences

Vellore Campus

N. Palanisami

Palanisamy Rajakannu

Murugavel Ramaswamy

Rajakannu P

Murugavel R.

Antiprismatic geometry

Heptacoordination

Monodentate ligand

Non-covalent aggregation

Fulltext

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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Inorganica Chimica Acta

Mononuclear and dinuclear copper(II) complexes with thiophenecarboxylic acid, [Cu(3-TCA)2(2,2′-bpy)] (1), [Cu(3-Me-2-TCA)2(H2O)(2,2′-bpy)] (2), [Cu(5-Me-2-TCA)2(H2O)(2,2′-bpy)] (3) and [Cu2(2,5-TDCA)(DMF)2(H2O)2(2,2′-bpy)2](ClO4)2 (4) (where 3-TCA = 3-thiophenecarboxylic acid; 3-Me-2-TCA = 3-methyl-2-thiophenecarboxylic acid; 5-Me-2-TCA = 5-methyl-2-thiophenecarboxylic acid; 2,5-TDCA = thiophene-2,5-dicarboxylic acid; 2,2′-bpy = 2,2′-bipyridyl; DMF = N,N-dimethylformamide), were synthesized. Compounds 1–4 were extensively characterized using both analytical and spectroscopic methods. Additionally, the solid-state structures of 1 and 4 were unambiguously established from single-crystal X-ray diffraction studies. The hexacoordinated Cu(II) centre in 1 (CuO4N2) is a distorted octahedral geometry whereas the pentacoodinated 4 (CuO3N2) has distorted square pyramidal geometry. Compounds 1 and 4 exhibit intermolecular hydrogen bonding which leads to the formation of two- and three-dimensional supramolecular architectures, respectively. Spectrophotometric and computational investigations suggest that these compounds bind with DNA in minor groove binding such that Kb = 4.9 × 10⁵ M⁻¹ and Ksv = 3.4 × 10⁵ M⁻¹, and binding score of −5.26 kcal mol⁻¹. The binding affinity of these complexes to calf thymus DNA is in the order 2 &gt; 3 &gt; 4 &gt; 1. Methyl-substituted thiophene ring increases the DNA binding affinity whereas unsubstituted thiophene ring DNA binding rate is reduced. The methyl group on the thiophene ring would sterically hinder π–π stacking of the ring with DNA base pairs, and subsequently they are involved in hydrophobic interaction with the DNA surface rather than partial intercalative interaction. Compounds 1–4 show pronounced activity against B16 mouse melanoma skin cancer cell lines as measured by MTT assay yielding IC50 values in the micromolar concentration range. The compounds could prove to be efficient anti-cancer agents, since at a concentration as low as 2.1 μg ml⁻¹ they exerted a significant cytotoxic effect in cancer cells whereas cell viability was not affected in normal cells.

Applied Organometallic Chemistry

Synthesis and structural and DNA binding studies of mono‐ and dinuclear copper(II) complexes constructed with ─O and ─N donor ligands: Potential anti‐skin cancer drugs

The structural characterization of tetranuclear cage-type cadmium(II) carboxylate [Cd4(2-cpida)2(2,2′-bpy)6]·(2,2-bpy)·(ClO4)·3H2O (1) (2-H3cpida&nbsp;=&nbsp;N-(2-carboxyphenyl)iminodiacetic acid, 2,2′-bpy&nbsp;=&nbsp;2,2′-bipyridine) is described. H-bonding interactions between three lattice water molecules form a V-shaped trimer (H2O)3, which is stabilized by 1. In addition, luminescence investigations revealed that 1 shows enhanced emissions as compared with free 2-H3cpida in the liquid state.

Journal of Coordination Chemistry

Structural and luminescent properties of a tetranuclear cage-type cadmium(II) carboxylate cluster containing a V-shaped water trimer

A mixed Cd(II) complex {[Cd(FcCOO)2(dpyam)(H2O)][Cd(dpyam)2 (H2O)2]·(ClO4)2·CH3OH} (1) (where FcCOO&nbsp;=&nbsp;ferrocenecarboxylic acid and dpyam&nbsp;=&nbsp;2,2′-dipyridylamine), has been synthesized and characterized by FT-IR, 1H &amp; 13C NMR, UV–Vis spectroscopy and elemental analysis. The molecular structure of compound 1 has been determined by the single crystal X-ray diffraction technique, which consists of mixed two different cadmium(II) complexes and two uncoordinated perchlorate ions. The crystal packing shows that the compound 1 self-assembled by intermolecular hydrogen bonding via pyridyl N–H⋯O and coordinated water O⋯H–O–H⋯O, to afford the molecule 2D supramolecular network. Compound 1 exhibits high-energy intraligand (π–π∗) fluorescence emission. In electrochemical studies of compound 1 shows negative potential compared with ferrocenecarboxylic acid due to formation of coordination complex with Cd ions. The antibacterial study against the distinct bacterial strains show compound 1 has significant activity.

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy

Monomeric mixed cadmium-2,2′-dipyridylamine complex derived from ferrocenecarboxylic acid: Structural, electrochemical and biological studies

Sterically encumbered 4-hydroxy-3,5-diisopropylbenzoic acid (H2diphba), bearing a carboxylic acid, a phenol and two iso-propyl substituents, has been investigated for the first time as a ligand and supramolecular synthon to isolate eight Zn(II) complexes, [Zn2(Hdiphba)3(OAc)(L)] (L=DMF(1) or pyz (2)), [Zn(Hdiphba)2(2,2'-bpy)] (3), [Zn(Hdiphba)2(1,10-phen)] (4), [Zn(Hdiphba)2(pz)2] (5) and [Zn2(Hdiphba)2(μ2-dmpz)2(Hdmpz)2] (6), [Zn(Hdiphba)2(4,4'-bpy)]n⋅4nCH3OH (7.4nCH3OH), [Zn2(Hdiphba)4(4,4'-azobpy)(H2O)2] (8⋅H2diphba), which have been structurally characterized. Compounds 1 and 2 are rare examples of symmetrically bridged triple-blade molecular tricarboxylate paddle-wheels which self-assemble into hexameric units. Compounds 3, 4 and 5 are mononuclear complexes, bearing two exposed phenolic –OH groups self-assembled into 2-D arrays via both hydrogen bonding and π-π stacking interactions. Compound 6 is a rare example of bis-pyrazolate bridged dinuclear Zn(II) complex with two pyrazole N−H and two phenolic -OH groups on the molecular periphery to form hydrogen bonds. The use of 4,4’-bpy leading to a zig-zag 1-D polymer 7 composed of [Zn(Hdiphba)2(4,4’-bpy)]n chains, positioned 10.77 Å apart. The 1-D channels of 7 are occupied by hydrogen bonded methanol with a rare (CH3OH)4 cluster as the repeating unit. Compound 8 is a discrete bimetallic complex, isolated with a free H2diphba ligand. The photoluminescence spectra of 1–8 exhibit ligand centered emission at around 325 nm. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

ChemistrySelect

Zinc Dialkylhydroxybenzoates with Unusual Structures: First Example of a Discrete Three-Blade Paddle-Wheel and a Solvent Engulfed Coordination Polymer

Reaction of [Mn(2,2′-bpy)2(OAc)](ClO4)(H 2O) with a series of aromatic carboxylic acids yields new Mn(II)carboxylates [Mn(2,2′-bpy)2(L)](ClO4)} 2 (1-3), [Mn(2,2′-bpy)2(L)2] (4-5) and [Mn(2,2′-bpy)2(L)(H2O)](ClO4) (6) (L = 2-aminobenzoate (2-aba) (1), 4-hydroxybenzoate (4-hba) (2), thiophene-2- carboxylate (2-tca) (3), 2-hydroxynapthoate (2-hnapa) (4), 3,5- diisopropylsalicylic acid (dipsa) (5), 2,4,6-triisopropylbenzoate (tipba) (6)). The new compounds have been characterized with the aid of elemental analysis, spectroscopy, and single-crystal X-ray diffraction studies. Compounds 1-3, which have been synthesized from less bulky carboxylic acids, are dimeric in the solid-state. Compounds 4-6, which are derived from more bulkier aromaric carboxylic acids, exist as monomeric complexes. In the case of 6, where very bulky 2,4,6-triisopropyl benzoic acid is used as the starting material, only one carboxylate ligand binds to the metal, resulting in a cationic complex. Interestingly in all the six complexes, the C-H hydrogen atoms of the 2,2′-bpy ligands are involved in extensive hydrogen bonding with the carboxylate oxygen atoms of the adjacent molecules and hence form non-covalent 1-D or 2-D aggregates in the solid state. © 2010 Elsevier B.V. All rights reserved.

Synthesis, spectral characterization, and single crystal X-ray structures of a series of manganese-2,2′-bipyridine complexes derived from substituted aromatic carboxylic acids

Chemical Reviews

Metal–Organic Frameworks and Self-Assembled Supramolecular Coordination Complexes: Comparing and Contrasting the Design, Synthesis, and Functionality of Metal–Organic Materials

Crystal Growth & Design

Metal [Zn(II), Cd(II)], 1,10-Phenanthroline Containing Coordination Polymers Constructed on the Skeleton of Polycarboxylates: Synthesis, Characterization, Microstructural, and CO2 Gas Adsorption Studies

Correction to Porous Nitrogen Rich Cadmium-Tetrazolate Based Metal Organic Framework (MOF) for H2 and CO2 Uptake

The Journal of Physical Chemistry C

Hydrogen Storage in New Metal–Organic Frameworks

Non-covalently aggregated zinc and cadmium complexes derived from substituted aromatic carboxylic acids: Synthesis, spectroscopy, and structural studies

Journal	Data powered by TypesetInorganica Chimica Acta
Publisher	Data powered by TypesetElsevier S.A.
ISSN	201693
Open Access	No