scholarly journals Structural diversity among some dialkyltin(IV) benzoate and related derivatives

2021 ◽  
Vol 77 (5) ◽  
pp. 209-220
Author(s):  
Anthony Linden ◽  
Tushar S. Basu Baul

The molecular structures of five diorganotin(IV) carboxylates, (I)–(V), can be categorized into two main well-known structural types for such Sn complexes. One is the mononuclear dialkytin(IV) carboxylates with an [R2Sn(LH)2]-type skew-trapezoidal bipyramid, where the alkyl ligands are in pseudo-axial positions and the O atoms from two asymmetrically coordinated bidentate carboxylate ligands are in the equatorial plane. This structure type is adopted by dibutylbis{(E)-2-hydroxy-5-[(3-methylphenyl)diazenyl]benzoato}tin(IV) cyclohexane hemisolvate, [Sn(C4H9)2(C14H11N2O3)2]·0.5C6H12, (I), dibenzylbis{(E)-5-[(4-bromophenyl)diazenyl]-2-hydroxybenzoato}tin(IV), [Sn(C7H7)2(C13H8BrN2O3)2], (II), and aquadibenzylbis(4-{(E)-[(Z)-4-hydroxypent-3-en-2-ylidene]amino}benzoato)tin(IV) benzene disolvate, [Sn(C7H7)2(C12H12NO3)2(H2O)]·2C6H6, (III), although the latter has an additional water ligand to give a distorted pentagonal bipyramidal coordination geometry in which the carboxylate groups are more symmetrically coordinated to the Sn atom than in (I) and (II). The other structure motif is that of the tetranuclear bis(dicarboxylatotetraorganodistannoxanes), {[R2Sn(LH)]2O}2, which contain an Sn4O2 core decorated with four bridging carboxylate ligands, plus two alkyl ligands at each SnIV centre. The complexes octabutyltetrakis{μ-(E)-4-[(4-hydroxy-3,5-dimethylphenyl)diazenyl]benzoato}di-μ3-oxido-tetratin(IV) ethanol disolvate, [Sn4(C4H9)8(C15H13N2O3)4O2]·2C2H6O, (IV), and octabutyltetrakis{(E)-3-[(2-hydroxybenzylidene)amino]propanoato}di-μ3-oxido-tetratin(IV), [Sn4(C4H9)8(C10H10NO3)4O2], (V), display this motif. The structures obtained correlate with the 1:1 and 1:2 stoichiometric ratios of the dialkyltin(IV) and carboxylic acid starting materials in the syntheses. The supramolecular structures arising from consideration of secondary Sn...O interactions and/or classic hydrogen bonds include discrete molecules for (V), centrosymmetric dimers for (I), extended chains for (II) and (III), and sheets for (IV).

2016 ◽  
Vol 72 (4) ◽  
pp. 313-325
Author(s):  
Anthony Linden ◽  
Tushar S. Basu Baul

The diorganotin(IV) complexes of 5-[(E)-2-aryldiazen-1-yl]-2-hydroxybenzoic acid are of interest because of their structural diversity in the crystalline state and their interesting biological activity. The structures of dimethylbis{2-hydroxy-5-[(E)-2-(4-methylphenyl)diazen-1-yl]benzoato}tin(IV), [Sn(CH3)2(C14H11N2O3)2], and di-n-butylbis{2-hydroxy-5-[(E)-2-(4-methylphenyl)diazen-1-yl]benzoato}tin(IV) benzene hemisolvate, [Sn(C4H9)2(C14H11N2O3)2]·0.5C6H6, exhibit the usual skew-trapezoidal bipyramidal coordination geometry observed for related complexes of this class. Each structure has two independent molecules of the SnIVcomplex in the asymmetric unit. In the dimethyltin structure, intermolecular O—H...O hydrogen bonds and a very weak Sn...O interaction link the independent molecules into dimers. The planar carboxylate ligands lend themselves to π–π stacking interactions and the diversity of supramolecular structural motifs formed by these interactions has been examined in detail for these two structures and four closely related analogues. While there are some recurring basic motifs amongst the observed stacking arrangements, such as dimers and step-like chains, variations through longitudinal slipping and inversion of the direction of the overlay add complexity. The π–π stacking motifs in the two title complexes are combinations of some of those observed in the other structures and are the most complex of the structures examined.


Author(s):  
M. J. Cox ◽  
E. R. T. Tiekink

AbstractThe crystal and molecular structures of four compounds of the general formula Hg(S


2019 ◽  
Vol 234 (3) ◽  
pp. 165-175 ◽  
Author(s):  
Yee Seng Tan ◽  
Hao Zhe Chun ◽  
Mukesh M. Jotani ◽  
Edward R.T. Tiekink

Abstract The crystal and molecular structures of the one-dimensional coordination polymer [Zn(S2COEt)2(4LH2)]n (1) and binuclear [Zn(S2COCy)2]2(4LH2) (2) are described, where 4LH2 is N,N′-bis(pyridin-4-ylmethyl)ethanediamide. In 1, the Zn(S2COEt)2 entities are linked by bidentate bridging 4LH2 ligands through the pyridyl-N atoms to generate a twisted supramolecular chain. As a result of monodentate xanthate ligands, the N2S4 donor set defines a distorted tetrahedral coordination geometry and, crucially, allows the participation of the non-coordinating sulfur atoms in supramolecular association. Thus, in the crystal amide-N–H···O(amide) and amide-N–H···S(thione) hydrogen bonds link chains into a three-dimensional architecture. The substitution of the ethyl group in the xanthate ligand with a cyclohexyl group results in very different structural outcomes. In 2, a binuclear molecule is observed with the coordination geometry for zinc being defined by chelating xanthate ligands and a pyridyl-N atom with the NS4 donor set defining a highly distorted geometry. In the molecular packing, amide-N–H···S(thione) hydrogen bonds stabilise a supramolecular chain along the a-axis and these are connected into a three-dimensional arrangement by methylene-C–H···O and methylene-C–H···π(pyridyl) interactions. The relative importance of the specified intermolecular interactions and weaker, contributing contacts has been revealed by an analysis of the calculated Hirshfeld surfaces of 1 and 2.


Author(s):  
Juan Granifo ◽  
Sebastián Suarez ◽  
Ricardo Baggio

The centrosymmetric dinuclear complex bis(μ-3-carboxy-6-methylpyridine-2-carboxylato)-κ3N,O2:O2;κ3O2:N,O2-bis[(2,2′-bipyridine-κ2N,N′)(nitrato-κO)cadmium] methanol monosolvate, [Cd2(C8H6NO4)2(NO3)2(C10H8N2)2]·CH3OH, was isolated as colourless crystals from the reaction of Cd(NO3)2·4H2O, 6-methylpyridine-2,3-dicarboxylic acid (mepydcH2) and 2,2′-bipyridine in methanol. The asymmetric unit consists of a CdIIcation bound to a μ-κ3N,O2:O2-mepydcH−anion, anN,N′-bidentate 2,2′-bipyridine group and anO-monodentate nitrate anion, and is completed with a methanol solvent molecule at half-occupancy. The Cd complex unit is linked to its centrosymmetric image through a bridging mepydcH−carboxylate O atom to complete the dinuclear complex molecule. Despite a significant variation in the coordination angles, indicating a considerable departure from octahedral coordination geometry about the CdIIatom, the Cd—O and Cd—N distances in this complex are surprisingly similar. The crystal structure consists of O—H...O hydrogen-bonded chains parallel toa, further bound by C—H...O contacts alongbto form planar two-dimensional arrays parallel to (001). The juxtaposed planes form interstitial columnar voids that are filled by the methanol solvent molecules. These in turn interact with the complex molecules to further stabilize the structure. A search in the literature showed that complexes with the mepydcH−ligand are rare and complexes reported previously with this ligand do not adopt the μ-κ3coordination mode found in the title compound.


2020 ◽  
Vol 76 (12) ◽  
pp. 1813-1817
Author(s):  
Masatoshi Mori ◽  
Takayoshi Suzuki

The crystal structures of the complexes (SP-4-2)-cis-bis[8-(dimethylphosphanyl)quinoline-κ2 N,P]nickel(II) bis(perchlorate) nitromethane monosolvate, [Ni(C11H12NP)2](ClO4)2·CH3NO2 (1), and (SP-4-2)-cis-bis[8-(dimethylphosphanyl)quinoline-κ2 N,P]platinum(II) bis(tetrafluoroborate) acetonitrile monosolvate, [Pt(C11H12NP)2](BF4)2·C2H3N (2), are reported. In both complex cations, two phosphanylquinolines act as bidentate P,N-donating chelate ligands and form the mutually cis configuration in the square-planar coordination geometry. The strong trans influence of the dimethylphosphanyl donor group is confirmed by the Ni—N bond lengths in 1, 1.970 (2) and 1.982 (2) Å and, the Pt—N bond lengths of 2, 2.123 (4) and 2.132 (4) Å, which are relatively long as compared to those in the analogous 8-(diphenylphosphanyl)quinoline complexes. Mutually cis-positioned quinoline donor groups would give a severe steric hindrance between their ortho-H atoms. In order to reduce such a steric congestion, the NiII complex in 1 shows a tetrahedral distortion of the coordination geometry, as parameterized by τ4 = 0.199 (1)°, while the PtII complex in 2 exhibits a typical square-planar coordination geometry [τ4 = 0.014 (1)°] with a large bending deformation of the ideally planar Me2Pqn chelate planes. In the crystal structure of 2, three F atoms of one of the BF4 − anions are disordered over two sets of positions with refined occupancies of 0.573 (10) and 0.427 (10).


1998 ◽  
Vol 53 (4) ◽  
pp. 469-475 ◽  
Author(s):  
Kazuhiko Ozutsumi ◽  
Shintaro Ohnishia ◽  
Hitoshi Ohtaki ◽  
Masaaki Tabatab

The local structure around the cobalt(II) ion in the reaction intermediate formed during the metal substitution reaction of the homodinuclear mercury(II) porphyrin (5,10,15,20-tetrakis(4- sulfonatophenyl)porphyrin; H2tpps4- ) complex with a cobalt(II) ion in an acetate buffer has been determined by the stopped-flow EXAFS method. The structure of the reactant and the product of the above reaction has also been determined by the same method. The coordination geometry around the cobalt(II) ion in the heterodinuclear intermediate, [Hg(tpps)Coll]2- , is six-coordinate octahedral with four additional water and/or acetate oxygen atoms. The Coll-N and Coll-O bond lengths in the intermediate are 212(2) and 221(1) pm, respectively. The product, [Coll(tpps)]4-, has a six-coordinate octahedral structure, the Coll-N and Coll-O bond lengths being 203(1) and 215(1) pm, respectively. The Coll-N bond length in the intermediate is ca. 9 pm longer than that in the product. The Coll-O bond length in the intermediate is also ca. 9 pm longer than that of 212(1) pm in the reactant, the cobalt(II) acetato complex, and ca. 6 pm longer than that in the product. The longer Coll-O bond in the intermediate as compared to those in the reactant and in the product appears to be responsible for the instability of the intermediate. The oxidized product, [Colll(tpps)]3-, has a six-coordinate structure with two additional Colll-O bonds. The Colll-N and Colll-O bond lengths are 189(1) and 197(2) pm, respectively, and are much shorter than those in [Coll(tpps)]4-.


1990 ◽  
Vol 45 (10) ◽  
pp. 1369-1382 ◽  
Author(s):  
Heindirk tom Dieck ◽  
Lutz Stamp

Diazadienes RN = CR′-CR′ = NR (DAD) form molecular complexes with copper(I) halides of composition (DAD)CuX, the structures of which vary from [(DAD)2Cu]+(CuCl2)⁻ with a non-tetrahedral bis(chelated) cation, over [(DAD)CuCl]2 with asymmetrically bridging chloro ligands to planar three-coordinate (DAD)CuCl. The composition of the isolated complexes depends on the relative concentrations or on the solvent. The “soft” coordination geometry of copper is underlined by the structure of the coordination polymer of composition (DAD)2Cu5Cl5, in which Cu atoms of coordination number 2, 3 and 4 and very irregular geometries are encountered and where the DAD ligands are exclusively bridging. Halide ions and sp2-nitrogen donors are very competitive. Bridging DAD ligands are also encountered in (DAD)Cu-Y with the less nucleophilic anions trifluoromethane-sulphonate or perchlorate. Crystal and molecular structures are established for all these coordination geometries and the causes are discussed for the coordination flexibility of copper(I)


2009 ◽  
Vol 74 (11) ◽  
pp. 1259-1271 ◽  
Author(s):  
Zeljko Jacimovic ◽  
Goran Bogdanovic ◽  
Berta Holló ◽  
Vukadin Leovac ◽  
Katalin Szécsényi-Mészáros

The work is concerned with the crystal and molecular structures of zinc(II) and mercury(II) complexes with 4-acetyl-3-amino-5-methyl-pyrazole (aamp) of the coordination formulae [Zn(NCS)2(aamp)2[ and (Haamp)2[Hg(SCN)4]. The zinc(II) complex was obtained by the reaction of a warm methanolic solution of aamp with a mixture of zinc(II) nitrate and ammonium thiocyanate, whereas the mercury(II) complex was prepared by the reaction of a warm ethanolic solution of aamp and a warm, slightly acidified aqueous solution of [Hg(SCN)4]2-. Both complexes have a tetrahedral geometry, which in the case of zinc complex is formed by monodentate coordination of two aamp molecules and two isothiocyanate groups. The Zn(II) and Hg(II) atoms have significantly deformed coordination geometry. In both crystal structures the pyrazole derivative has a planar form, probably stabilized by an intramolecular N-H???O hydrogen bond. Apart from the X-ray structural analysis, the isolated complexes were characterized by elemental analysis, IR spectroscopy, conductometric measurements and thermal analysis.


2018 ◽  
Vol 74 (5) ◽  
pp. 599-603 ◽  
Author(s):  
Yan-Ju Liu ◽  
Di Cheng ◽  
Ya-Xue Li ◽  
Xiang-Ru Meng ◽  
Huai-Xia Yang

In recent years, N-heterocyclic carboxylate ligands have attracted much interest in the preparation of new coordination polymers since they contain N-atom donors, as well as O-atom donors, and have a rich variety of coordination modes which can lead to polymers with intriguing structures and interesting properties. A new two-dimensional coordination polymer, namely poly[[μ3-2,2′-(1,2-phenylene)bis(4-carboxy-1H-imidazole-5-carboxylato)-κ6 O 4,N 3,N 3′,O 4′:O 5:O 5′]manganese(II)], [Mn(C16H8N4O8)] n or [Mn(H4Phbidc)] n , has been synthesized by the reaction of Mn(OAc)2·4H2O (OAc is acetate) with 2,2′-(1,2-phenylene)bis(1H-imidazole-4,5-dicarboxylic acid) (H6Phbidc) under solvothermal conditions. In the polymer, each MnII ion is six-coordinated by two N atoms from one H4Phbidc2− ligand and by four O atoms from three H4Phbidc2− ligands, forming a significantly distorted octahedral MnN2O4 coordination geometry. The MnII ions are linked by hexadentate H4Phbidc2− ligands, leading to a two-dimensional structure parallel to the ac plane. In the crystal, adjacent layers are further connected by N—H...O hydrogen bonds, forming a three-dimensional structure in the solid state.


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