0000000000175567
AUTHOR
Michael G. B. Drew
Use of a reduced Schiff-Base ligand to prepare novel chloro-bridged chains of rare Cu(II) trinuclear complexes with mixed azido/oxo and chloro/oxo bridges.
Two mixed bridged one-dimensional (1D) polynuclear complexes, [Cu(3)L(2)(mu(1,1)-N(3))(2)(mu-Cl)Cl](n) (1) and {[Cu(3)L(2)(mu-Cl)(3)Cl].0.46CH(3)OH}(n) (2), have been synthesized using the tridentate reduced Schiff-base ligand HL (2-[(2-dimethylamino-ethylamino)-methyl]-phenol). The complexes have been characterized by X-ray structural analyses and variable-temperature magnetic susceptibility measurements. In both complexes the basic trinuclear angular units are joined together by weak chloro bridges to form a 1D chain. The trinuclear structure of 1 is composed of two terminal square planar [Cu(L)(mu(1,1)-N(3))] units connected by a central Cu(II) atom through bridging nitrogen atoms of end…
A unique example of structural and magnetic diversity in four interconvertible copper(II)-azide complexes with the same schiff base ligand: a monomer, a dimer, a chain, and a layer.
Four new Cu(II)-azido complexes of formula [CuL(N(3))] (1), [CuL(N(3))](2) (2), [Cu(7)L(2)(N(3))(12)](n) (3), and [Cu(2)L(dmen)(N(3))(3)](n) (4) (dmen = N,N-dimethylethylenediamine) have been synthesized using the same tridentate Schiff base ligand HL (2-[1-(2-dimethylaminoethylimino)ethyl]phenol, the condensation product of dmen and 2-hydroxyacetophenone). The four compounds have been characterized by X-ray structural analyses and variable-temperature magnetic susceptibility measurements. Complex 1 is mononuclear, whereas 2 is a single mu-1,1 azido-bridged dinuclear compound. The polymeric compound 3 possesses a 2D structure in which the Cu(II) ions are linked by phenoxo oxygen atoms and t…
A ferromagnetic methoxido-bridged Mn(III) dimer and a spin-canted metamagnetic μ(1,3)-azido-bridged chain.
Two new Mn(III) complexes of formulas [MnL(1)(N(3))(OMe)](2) (1) and [MnL(2)(N(3))(2)](n) (2) have been synthesized by using two tridentate NNO-donor Schiff base ligands HL(1){(2-[(3-methylaminoethylimino)-methyl]-phenol)} and HL(2) {(2-[1-(2-dimethylaminoethylimino)methyl]phenol)}, respectively. Substitution of the H atom on the secondary amine group of the N-methyldiamine fragment of the Schiff base by a methyl group leads to a drastic structural change from a methoxido-bridged dimer (1) to a single μ(1,3)-azido-bridged 1D helical polymer (2). Both complexes were characterized by single-crystal X-ray structural analyses and variable-temperature magnetic susceptibility measurements. The ma…
(Ni2), (Ni3), and (Ni2 + Ni3): A Unique Example of Isolated and Cocrystallized Ni2 and Ni3 Complexes
Structural and magnetic characterization of compound {[Ni(2)(L)(2)(OAc)(2)][Ni(3)(L)(2)(OAc)(4)]}.2CH(3)CN (3) (HL = the tridentate Schiff base ligand, 2-[(3-methylamino-propylimino)-methyl]-phenol) shows that it is a rare example of a crystal incorporating a dinuclear Ni(II) compound, [Ni(2)(L)(2)(OAc)(2)], and a trinuclear one, [Ni(3)(L)(2)(OAc)(4)]. Even more unusual is the fact that both Ni(II) complexes, [Ni(2)(L)(2)(OAc)(2)] (1) and [Ni(3)(L)(2)(OAc)(4)(H(2)O)(2)].CH(2)Cl(2).2CH(3)OH (2), have also been isolated and structurally and magnetically characterized. The structural analysis reveals that the dimeric complexes [Ni(2)(L)(2)(OAc)(2)] in cocrystal 3 and in compound 1 are almost i…
Coordination Polymers Containing Manganese(II)-Azido Layers Connected by Dipyridyl-tetrazine and 4,4′-Azobis(pyridine) Linkers
Two new polynuclear manganese(II) complexes [Mn(dptz)(N(3))(2)](n) (1) and [Mn(azpy)(N(3))(2)](n) (2) (where dptz = dipyridyl-tetrazine and azpy = 4,4'-azobis(pyridine)) have been synthesized by self-assembly of the ligand azide, together with dptz and azpy as secondary spacers. The compounds are characterized by single-crystal X-ray diffraction analyses and variable-temperature magnetic measurements. The structural analyses reveal that in complex 1, which is the first reported Mn(II) complex with the ligand dptz, two μ(1,3) bridging azides connect neighboring manganese ions in a zigzag manner to generate a neutral two-dimensional (2D) sheet which is further connected by the dptz ligands to…
Synthesis, structural characterization and electrochemical activity of oxidovanadium(IV/V) complexes of a diprotic ONS chelating ligand
Abstract The present work reports the chemistry of a few oxidovanadium(IV) and (V) complexes of the ONS chelating ligand S-benzyl-β-N-(2-hydroxyphenylethylidine) dithiocarbazate (H2L). Major objective of this work is to arrive at some general conclusions about the influence of binding environment generated by the replacement of an O-donor center by a S-donor point in a ligand (of a similar arrangement of the other O- and N-donor points) on the redox behavior and on the structural features of comparable [VO(OEt)(ONS)] and [VO(OEt)(ONO)] complexes. Synthesis, characterization by various physicochemical techniques (UV–Vis, IR, EPR and elemental analysis), exploration of electrochemical activit…
Rare examples of diphenoxido-bridged trinuclear Ni II 2 Fe III complexes with a reduced salen type Schiff base ligand: Structures and magnetic properties
Abstract Three new trinuclear hetero-metallic complexes, [(NiLR)2Fe(N3)3] (1), [(NiLR(H2O))2Fe(C6H5CH2CO2)2]·(HSO4) (2) and [(NiLR(H2O))2Fe(C6H5CO2)2]·(HSO4)·(H2O)·(CH2Cl2) (3) have been synthesized using [NiLR] as a “metalloligand” (where H2LR = N,N′-bis(2-hydroxybenzyl)-1,3-propanediamine). All complexes have been characterized by elemental analysis, spectroscopic methods, single crystal XRD and magnetic study. In the angular trinuclear units of 1, the two terminals [NiLR] coordinate through double phenoxido bridges to the central FeIII ion which is penta-coordinated having terminally coordinated azide ion. The two terminal NiII centers are connected to each other and also to neighbouring…
A rare case of solution and solid state inter-conversion of two copper(II) dimers and a copper(II) chain
Abstract Three Cu(II)-azido complexes of formula [Cu2L2(N3)2] (1), [Cu2L2(N3)2]·H2O (2) and [CuL(N3)]n (3) have been synthesized using the same tridentate Schiff base ligand HL (2-[(3-methylaminopropylimino)-methyl]-phenol), the condensation product of N-methyl-1,3-propanediamine and salicyldehyde). Compounds 1 and 2 are basal-apical μ-1,1 double azido bridged dimers. The dimeric structure of 1 is centrosymmetric but that of 2 is non-centrommetric. Compound 3 is a μ-1,1 single azido bridged 1D chain. The three complexes interconvert in solution and can be obtained in pure form by carefully controlling the synthetic conditions. Compound 2 undergoes an irreversible transformation to 1 upon de…
A novel Cu(II) dimer containing oxime-hydrazone Schiff base ligands with an unusual mode of coordination: Study of magnetic, autoreduction and solution properties
Abstract Synthesis of a new hydrazone based Schiff base ligand, 3-methylpyrazole-5-carbohydrazone of 2,3-butanedione monoxime (HL) is reported. The reaction of Cu(ClO4)2·6H2O with HL in any ratio in ethanol affords the dinuclear complex [CuL(EtOH)]2(ClO4)2·2H2O (1). An unusual coordination mode of the ligand was observed, in which the ligand forms stable six and five membered chelate rings around the metal centres without enolization of the carbonyl group of the hydrazone moiety. The same coordination behavior of the ligand was observed in its cobalt(III) complex. The reaction of CoCl2·6H2O in methanol with the ligand HL affords the mononuclear complex [CoL2]Cl (2). Both 1 and 2 were charac…
2-Amino-2-methyl-1,3-propanediol (ampdH2) as ligand backbone for the synthesis of cobalt complexes: Mononuclear Co(II), binuclear Co(II,III) and hexanuclear Co(II,III)
Abstract Three cobalt complexes have been synthesized using 2-amino-2-methyl-1,3-propanediol (ampdH2) and its Schiff base derivative ligands and structurally characterized. The three complexes 1, 2 and 3 are very different and consist of mononuclear Co(II), mixed-valence binuclear Co(II,III) and mixed-valence hexanuclear Co(II,III) complexes respectively. The properties of the coordinated donor atoms of the ligand play the predominant role in stabilizing the oxidation states of the cobalt centers. The presence of intermolecular hydrogen bonds in 1 via non-coordinating perchlorate ions lead to the formation of a 1D-Chain network while a sheet-like 2D network was observed in 3.
Two Polymorphic Forms of a Six-Coordinate Mononuclear Cobalt(II) Complex with Easy-Plane Anisotropy: Structural Features, Theoretical Calculations, and Field-Induced Slow Relaxation of the Magnetization.
A mononuclear cobalt(II) complex [Co(3,5-dnb)2(py)2(H2O)2] {3,5-Hdnb = 3,5-dinitrobenzoic acid; py = pyridine} was isolated in two polymorphs, in space groups C2/c (1) and P21/c (2). Single-crystal X-ray diffraction analyses reveal that 1 and 2 are not isostructural in spite of having equal formulas and ligand connectivity. In both structures, the Co(II) centers adopt octahedral {CoN2O4} geometries filled by pairs of mutually trans terminal 3,5-dnb, py, and water ligands. However, the structures of 1 and 2 disclose distinct packing patterns driven by strong intermolecular O-H···O hydrogen bonds, leading to their 0D→2D (1) or 0D→1D (2) extension. The resulting two-dimensional layers and one-…
Playing with different metalloligands [NiL] and Hg to [NiL] ratios to tune the nuclearity of Ni(II)–Hg(II) complexes: Formation of di-, tri-, hexa- and nona-nuclear Ni–Hg clusters
Abstract Five new hetero-metallic nickel(II)–mercury(II) complexes, [(NiL1)HgCl2] (1), [(NiL1)2HgCl2] (3), [(NiL1)2Hg(N3)2] (4), [{(NiL2)2Hg(N3)(μ1,1-N3)}2] (5) and [{(NiL2)2Hg(N3)(μ1,1-N3)HgCl2}2{Hg(N3)(μ1,1-N3)}] (6) have been synthesized by reacting metalloligands [NiL1] or [NiL2] (where H2L1 is N,N′-bis(salicylidene)-1,2-ethylenediamine and H2L2 is N,N′-bis(salicylidene)-1,3-propanediamine) with HgX2 (X− = Cl− or N3−) at different molar ratios. All five complexes have been characterised by X-ray single-crystal structural, elemental and spectroscopic analyses. In complex 1, the Hg(II) ion is coordinated to two phenoxido oxygen atoms of one [NiL1] moiety and two terminal chloride ions to …
The Crucial Role of Polyatomic Anions in Molecular Architecture: Structural And Magnetic Versatility of Five Nickel(II) Complexes Derived from A N,N,O-Donor Schiff Base Ligand
Five new nickel(II) complexes [Ni(2)L(2)(N(3))(2)(H(2)O)(2)] (1), [Ni(2)L(2)(NO(3))(2)] (2), [Ni(2)L(2)(O(2)CPh)(CH(3)OH)(2)]ClO(4).0.5CH(3)OH (3), [Ni(3)L(2)(O(2)CPh)(4)] (4), and [Ni(2)L(2)(NO(2))(2)](n) (5) have been synthesized by using a tridentate Schiff base ligand, HL (2-[(3-Methylamino-propylimino)-methyl]-phenol), and the polyatomic monoanions N(3)(-), NO(3)(-), PhCOO(-), or NO(2)(-). The complexes have been structurally and magnetically characterized. The structural analysis reveals that in all five complexes, the Ni(II) ions possess a distorted octahedral geometry. Complexes 1 and 2 are dinuclear with di-mu-1,1-azido and di-mu(2)-phenoxo bridges, respectively. Complex 3 is also …
Isolation of Two Different Ni2Zn Complexes with an Unprecedented Cocrystal Formed by One of Them and a “Coordination Positional Isomer” of the Other
A new homometallic trinuclear Ni(II) complex [(NiL)2Ni(NCS)2] (1) and three heterometallic trinuclear Ni(II)-Zn(II)-Ni(II) complexes [(NiL)2Zn(NCS)2] (2), [(NiL)2Zn(NCS)2(CH3OH)2]·2CH3OH (3) and {[(NiL)2Zn(NCS)2(CH3OH)2]} {[(NiL)2Zn(NCS)2]} (4) have been synthesized by using the "complex as ligand" approach with the "metalloligand" [NiL] (H2L = N,N'-bis(salicylidene)-1,3-propanediamine) and thiocyanate in different ratios. All the complexes have been structurally and magnetically characterized. In the isomorphous complexes 1 and 2, the two terminal square planar Ni atoms and the central octahedral nickel atom (in 1) or zinc atom (in 2) are arranged in a bent structure where two cis κN-SCN(-…
Formation of a dinuclear and a trinuclear Ni(II) complex on slight variation of experimental conditions: Structural analysis and magnetic properties
Abstract A diphenoxido bridged dinuclear Ni(II) complex [Ni2L2(NO2)2] (1) and a μ2 and μ3-phenoxido, μ3-hydroxido, and μ2-nitrito (1κO:2κN) bridged trinuclear Ni(II) complex [Ni3L3(OH)(NO2)]·ClO4 (2), have been synthesized using a tridentate reduced Schiff base ligand HL (HL = 2-[(2-dimethylamino-ethylamino)-methyl]-phenol). Both complexes were characterized by X-ray structure determination and variable-temperature magnetic susceptibility measurements. In both complexes the nickel atoms are six-coordinated with a distorted octahedral environment. The interesting feature of the trimeric complex 2 is that the three mononuclear units are assembled around a μ3-hydroxido ion in such a way that t…
Mononuclear and tetranuclear Fe(III) complexes with two different types of N, O donor Schiff base ligands
Abstract A mononuclear Fe(III) complex of a tetradentate N 2 O 2 donor Schiff base ligand derived from 3-ethoxysalicaldehyde and ethylenediamine has been reported. In addition two tetranuclear Fe(III) complexes with discrete Fe 4 III (μ 4 -O) cores have been synthesized and characterized using two Schiff base ligands (H 2 L 1–2 ) derived from two different aromatic acid hydrazides and diacetyl monoxime. The mononuclear Fe(III) and one of the tetranuclear Fe(III) complexes have been structurally characterized by single-crystal X-ray crystallography. The mononuclear complex has a highly distorted octahedral geometry. The tetranuclear Fe(III) complexes are found to be rare examples with discre…
Malonato complexes of oxidovanadium(IV): Synthesis, structural characterization and exploration of their insulin mimetic properties
Abstract Several bis-malonatooxidovanadium(IV) complexes of the general type [M2(H2O)n][VO(mal)2(H2O)] (where M = Li(1), Na(2), K(3), Cs(4) and NH4(5); n = 3.5, 1, 3, 1 and 1, respectively) were isolated in good yield and high purity. These complexes were fully characterized by various physicochemical techniques (elemental analysis, UV–Vis, IR, EPR, CV, etc.) complexes 1, 2 and 3 were structurally characterized by single crystal X-ray diffraction technique. In vivo antidiabetic properties of bis-malonato complexes 1, 2, 3 and 5 have been studied using Streptozotocin induced diabetic rats. Significant lowering of blood sugar level has been noticed. At the same time these complexes were found…
Synthesis and characterization of four novel manganese(II) chains formed by 4,4′-azobis(pyridine) and benzoate or nitrobenzoates: Stabilization of unusual ladder structures
Abstract Four new manganese(II) coordination polymers: [Mn(4,4′-azpy)(C6H5COO)2](4,4′-azpy)0.5 (1), [Mn(4,4′-azpy)(p-(NO2)C6H4COO)2] (2), [Mn(4,4′-azpy)(m-(NO2)C6H4COO)2] (3) and [Mn(4,4′-azpy)(o-(NO2)C6H4COO)2(H2O)2] (4), where 4,4′-azpy = 4,4′-azobis(pyridine), have been synthesized by self-assembly of MnX2 (X = benzoate, p-, m-, or o-nitrobenzoates) together with 4,4′-azpy. All four complexes were characterized by elemental analyses, IR spectroscopy, thermal analyses, single-crystal X-ray diffraction analyses and variable-temperature magnetic measurements. The structural analyses reveal that complexes 1, 2 and 3 feature a 1D molecular ladder formed by syn–syn (complex 1) or syn–anti (com…
CCDC 985535: Experimental Crystal Structure Determination
Related Article: Takuya Kuwabara, Jing Dong Guo, Shigeru Nagase, Masaichi Saito|2014|Angew.Chem.,Int.Ed.|53|434|doi:10.1002/anie.201308565
CCDC 985534: Experimental Crystal Structure Determination
Related Article: Takuya Kuwabara, Jing Dong Guo, Shigeru Nagase, Masaichi Saito|2014|Angew.Chem.,Int.Ed.|53|434|doi:10.1002/anie.201308565
CCDC 985536: Experimental Crystal Structure Determination
Related Article: Takuya Kuwabara, Jing Dong Guo, Shigeru Nagase, Masaichi Saito|2014|Angew.Chem.,Int.Ed.|53|434|doi:10.1002/anie.201308565
CCDC 939232: Experimental Crystal Structure Determination
Related Article: Paramita Kar, Michael G. B. Drew, Carlos J. Gómez-García, and Ashutosh Ghosh|2013|Inorg.Chem.|52|1640|doi:10.1021/ic302548z
CCDC 985537: Experimental Crystal Structure Determination
Related Article: Takuya Kuwabara, Jing Dong Guo, Shigeru Nagase, Masaichi Saito|2014|Angew.Chem.,Int.Ed.|53|434|doi:10.1002/anie.201308565
CCDC 1477729: Experimental Crystal Structure Determination
Related Article: Subhadip Roy, Itziar Oyarzabal, Julia Vallejo, Joan Cano, Enrique Colacio, Antonio Bauza, Antonio Frontera, Alexander M. Kirillov, Michael G. B. Drew, and Subrata Das|2016|Inorg.Chem.|55|8502|doi:10.1021/acs.inorgchem.6b01087
CCDC 1477730: Experimental Crystal Structure Determination
Related Article: Subhadip Roy, Itziar Oyarzabal, Julia Vallejo, Joan Cano, Enrique Colacio, Antonio Bauza, Antonio Frontera, Alexander M. Kirillov, Michael G. B. Drew, and Subrata Das|2016|Inorg.Chem.|55|8502|doi:10.1021/acs.inorgchem.6b01087
CCDC 939231: Experimental Crystal Structure Determination
Related Article: Paramita Kar, Michael G. B. Drew, Carlos J. Gómez-García, and Ashutosh Ghosh|2013|Inorg.Chem.|52|1640|doi:10.1021/ic302548z