Structural chemistry of organotin(IV) complexes

The amazing structural diversity in organotin compounds is discussed in the systems containing -O and -S donor ligands. It is demonstrated that there exist a fascinating range of structural diversity for organotin(IV) complexes, including differences in coordination number and molecular geometry. The difference in structure is correlated with the nature of tin and ligand bonded R groups. Despite the large number of different structures found in organotin(IV) carboxylates, there is limited range of coordination geometries about the Sn atom. The four coordinated Sn atom in triorganotin(IV) complexes is invariably distorted tetrahedral and five coordinated Sn is distorted trigonal bipyramidal. A large range has been observed for diorganotin carboxylate structures, where five, six and seven coordinate geometries have been reported. The Sn atom in mono-organotin has only been demonstrated to exist in distorted octahedral geometries (the single exception being a pentagonal bipyramidal geometry). In the case of organotin(IV) complexes of S donor ligands, it has been shown that there exists a rich diversity in Sn atom geometries and coordination modes of the sulfur donor ligands themselves. As in related carboxylate systems, the assignment of coordination numbers to the Sn centers in some compounds is controversial. As a general trend, it has been shown that, the overall coordination number at the Sn atom decreases with the increasing number of organic substituents at the Sn atom. This phenomenon is usually achieved by increased asymmetry in the mode of coordination of the sulfur donor ligands.     

Formation of a novel trinuclear spirostannoxane tin(IV) compound. Crystal and molecular structure of [Sn(nBu)(Cl)[(OCH2CH2S)2Sn(nBu)]2] and the stannolane [(nBu)Sn(SCH2CH2O)SCH2CH2OH

The reaction of nBuSnCl3 and the sodium salt of 2-mercaptoethanol (1:1) in ethanol gave the compound Sn(nBu)(Cl)[(OCH2CH2S)2Sn(nBu)]2 (1). [(nBu)Sn(SCH2CH2O)SCH2CH2OH] (2) was initially isolated from the reaction of 1 with nBuMgCl as a rearrangement product but was also synthesized from nBuSn(O)OH and two molar equivalents of 2-mercaptoethanol. Both compounds were characterized by means of IR, 119Sn, 13C, and 1H NMR, FAB mass spectroscopy, and elemental analyses. The structures were determined by single-crystal X-ray diffraction. 1 crystallizes in the monoclinic Cc space group (a = 18.492(3) A, b = 17.329(2) A, c = 10.787(1) A, beta = 111.88(1) degrees, Z = 4), while 2 crystallizes in the orthorhombic Pbca space group (a = 14.458(2) A, b = 10.393(1) A, c = 16.479(2) A, Z = 8). 1 is a trimetallic Tin(IV) compound in which the central atom is in 6-fold coordination, while the two remaining tin atoms show 5-fold coordination. Both pentacoordinated tin atoms are bonded to a butyl group and to the oxygen and the sulfur atoms from two [OCH2CH2S]2- ligands forming two stannolanes, which are fused with the hexacoordinated tin atom forming a distannoxane system. This arrangement is quite different from previous ladder or staircase structures. NMR data point to maintenance of this structure in solution. 2 consists of [(nBu)Sn(SCH2CH2O)(SCH2CH2OH)] units, which are associated via intermolecular Sn-O interactions building up a dimer. The tin atom forms two "stannolane" units by interaction with [OCH2CH2S]2- and [HOCH2CH2S]- ligands.     

The reaction of diphenyltin (IV) or triphenyltin (IV) chloride with 3,4,5-trimethoxybenzoyl salicylahydrazone. The crystal structure of Ph2[(MeO)3C6H2C(O)N2CHC6H4O]Sn

The title complex has been synthesized by the reaction of diphenyltin(IV) or triphenyltin(IV) chloride with 3,4,5-trimethoxybenzoyl salicylahydrazone and characterized by ¹H, ¹³C, ¹¹⁹Sn NMR, and IR spectral studies. An X-ray analysis shows that the ligand is tridentate and approximately planar and the central tin atom is in a distorted five-coordinate trigonal bipyramidal geometry. The complex crystallizes in the monoclinic space group C2/c with a = 29.194(4), b = 10.117(1), c = 22.524(3) Å, β = 124.44(2)°, V = 5486.5(8) ų, Z = 8. The Sn C bond lengths are 2.123(9) and 2.116(7) Å, and the bond length between the tin atom and the coordinating nitrogen atom (Sn–N bond) is 2.152(6) Å. The C Sn C bond angle and the bond angle between the tin atom and the two axially positioned oxygen atoms are 129.1(1) and 156.17(9)°, respectively. The structure was refined to final R = 0.056 and R_w = 0.074 for 4145 observed reflections with I > 3σ(I). © John Wiley & Sons, Inc.     

Synthesis and Crystal Structure of a Novel Monomeric Di-butyltin Dicarboxylate: nBu2Sn[O2CCH2CH(4-ClC6H4)Ge(OCH2CH2)3N]2.H2O

nBu2Sn[O2CCH2CH(4-ClC6H4)Ge(OCH2CH2)3N]2.H2O(Mr=1053.66) is an air-stable compound which crystallizes in the monoclinic space group C2/c with a=21.182(5), b=12.174(3), c=17.108(4) , β=99.59(2)°, V=4350(3) 3, Z=4, F(000)=2104, μ=2.104 mm-1. The refinement of structure with I≥3σ(I) for 1819 reflections converged at R=0.045. The coordination geometry around the Sn atom is best described as an askew-pentagonal bipyramid, in which four carboxylate oxygen atoms( Sn(1)-O(5), Sn(1)-O(5a)=2.099 and Sn(1)-O(4), Sn(1)-O(4a)=2.158 ) and an oxygen atom from an aqua ligand comprise the pentagonal plane, with two butyl groups occupying axial positions.     

In vitro antitumor and antibacterial assay of organotin(IV) complexes of 2,3-methylenedioxybenzoic acid; X-ray crystal structure of [(C2H5)2Sn(C8H5O4)2]

New organotin(IV) compounds containing the carboxylate ligand 2,3-methylenedioxybenzoic acid (HL) have been synthesized with the general formula R₂SnL₂ (R = Me, Et, n-Bu, Ph and n-Oct) and R₃SnL (R = n-Bu). All compounds have been studied in the solution state by multinuclear NMR (¹H, ¹³C and ¹¹⁹Sn) by using the non-coordinating solvent and also in solid sate by FTIR, mass spectrometry and X-ray crystallography. Spectroscopic data have shown that methylenedioxy moiety does not coordinate with tin atom and the coordination site is actually -COO group, as is proved by X-ray structure determination. The solid state structure of compound (2) has been determined by X-ray crystallography which shows that the complex (2) has distorted octahedral geometry. These complexes have been evaluated in vitro against crown gall tumor and antibacterial activity. Interesting results were noticed during the bio-activity screenings, which proved their in vitro biological potential and possible use as drugs.     

Crystal structure and heat capacity of the mixed-valence trinuclear iron monoiodoacetate complex, [Fe(III)2Fe(II)O(O2CCH2I)6(H2O)3][Fe(III)3O(O2CCH2I)6(H2O)3]I

The crystal structure of a trinuclear iron monoiodoacetate complex was determined. Although it has been incorrectly characterized as [Fe₃O(O₂CCH₂I)₆(H₂O)₃], the correct chemical formula turned out to be [Fe(III)₂Fe(II)O(O₂CCH₂I)₆(H₂O)₃]-[Fe(III)₃O(O₂CCH₂I)₆(H₂O)₃]I (1). The two kinds of Fe₃O molecules (Fe(III)₂Fe(II)O and Fe(III)₃O) are crystallographically indistinguishable. All the Fe atoms are crystallographically equivalent because of a crystallographic threefold symmetry. Heat capacities of 1 seem to exhibit no thermal anomaly in the temperature range 5.5–309 K, although the valence detrapping phenomenon has been observed in this temperature range. This fact indicates that the valence-detrapping phenomenon in 1 occurs without any phase transition, leading 1 to a glassy state, probably because the crystal of 1 is just like a solid solution of distorted mixed-valence Fe(III)₂Fe(II)O molecules and permanently undistorted Fe(III)₃O molecules which may act as an inhibitor for a cooperative valence-trapping.     

A new route to prepare the mixed oxo-ethylidyne-capped trinuclear tungsten(IV) cluster and the crystal structure of H2Na3[W3O(CCH3)-(O2CCH3)6(H2O)3][H2W12O40]·13.5H2O

The synthesis and the structural characterization of the title compound H₂Na₃[W₃O(CCH₃)-(O₂CCH₃)₆(H₂O)₃][H₂W₁₂O₄₀]·13.5H₂O are described. It is known that the mixed oxo-ethylidynecapped tritungsten cluster can be obtained by Zn dust reduction of Na₂WO₄·2H₂O in acetic anhydride. The title compound has been characterized by X-ray diffraction, UV/VIS and ¹H NMR spectra. The tungsten atoms in the cluster cation and anion are in the oxidation states of W(IV) and W(VI) respectively. The crystal is rhombohedral with the space group R32, a = 17.058 (3)Å, c = 49.665 (9)Å, γ=120°, V=12516(9)ų, Z=6, final R = 0.037 for 2071 reflections with I ≥3σ (I). Both the cluster cation and anion have a C₃ symmetry. The important interatomic distances in angstroms for the cluster cation are: W—W, 2.730(2); W—μ₃?O, 2.00; W—O (carboxy1), 2.12; W—O_t 2.18 (2).     

The crystal structure of bromotris(tetracarbonylcobalt)tin(IV)

Crystal of BrSn[Co(CO)₄]₃ are hexagonal, a = 10.20, c = 11.81 å, space group P6₃. The molecule comparises a central tin atom, surrounded tetrahedrally by the bromine atom and three Co(CO)₄ groups. The SnCo bond length is 2.60 å.     

The chemistry and the stereochemistry of poly(N-alkyliminoalanes) : IV. The preparation and crystal structure of [H(HAlN-i-Pr)5AlH2]·LiH/Et2O

The compound [H(HAlN-i-Pr)₅AlH₂]·LiH/Et₂O has been prepared, and its crystal and molecular structure has been determined from single-crystal, three-dimensional X-ray diffractometer data. The molecular structure is a pseudohexameric cage, consisting of a five-membered fragment, AlNAlNAl, crosslinked to a six-membered cyclohexane type ring, (AlN)₃. The hydrogen atom of LiH is indistinguishable from the other hydridic hydrogens, so that the N-isopropyliminoalane part of the molecule may be considered as an anion with a formal charge of ?1. The lithium cation is linked to two adjacent molecules through three LiHAl bridges, the fourth position of its tetrahedral coordination being occupied by the oxygen of diethyl ether. Large distortions of the tetrahedral valence angles occur, both on the aluminum atoms and on the nitrogen atoms, together with a noticeable spread of the AlN bond lengths, averaging 1.919(4) Å. Colourless crystals of the compound have the following crystal data: orthorhombic space group Pna2₁; a = 19.76(2), b = 10.38(1), c = 16.60(2) Å; Z = 4; calculated density 1.048 g/cm³. The structure has been refined by block-matrix least-squares methods, using 2487 independent reflections, to an usual R factor of 5.9%.     

Rate constants for tsomerization of C6H5C(SC6H5)2 ĆH2 radicals to C6H5Ć(SC6H5)CH2SC6H5 radicals based on EPR data

Conclusions The parameters of the Arrhenius equation for the isomerization of PhC(SPh)₂H₂ radicals to Ph(SPh)CH₂. SPh radicals are in agreement with an intramolecular character of the rearrangement, with a 1,2-migration of the thiyl group. These parameters were calculated on the basis of the data that were obtained by the EPR method in the range 10–70°.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2596–2597, November, 1982.     

The preparation and X-ray crystal structure of [Ru(SC6F52{P(C6H5)2(H4C6H-2)}2]

The complex [Ru(SC₆F₅)₂(PPh₃)₂] has been prepared from [RuCl₂(PPh₃)₃] and [Pb(SC₆F₅)₂] and shown by X-rays to have a pseudo-octahedral structure apparently with two RuHC interactions. It reacts with CO to give [Ru(SC₆F₅)₂-(CO)₂(PPh₃)₂].     

A layered tin(II) phosphonate, [Sn(C6H5O3P)]n

Poly­[tin(II)‐μ‐phenyl­phospho­nato], [Sn(C₆H₅O₃P)]_n, was synthesized solvothermally at 423 K and crystallized in the monoclinic system, space group Cc. The inorganic layers consist of alternating pyramidal Sn and tetrahedral P centers, joined by doubly bridging O atoms. The corner‐sharing SnO₃ and PO₃C₆H₅ polyhedra define a corrugated layer of six‐membered rings. The layers are connected along the unique b axis by interdigitated phenyl rings of the phenyl­phospho­nate groups.     

Macrocyclic organotin(IV) carboxylates based on benzenedicarboxylic acid derivatives: Syntheses, crystal structures and antitumor activities

Six new organotin carboxylates based on 1,3-benzenedicarboxylic acid and 1,4-benzenedicarboxylic acid derivatives, namely (Ph₃Sn)₂(2,5-L¹)(C₂H₅OH)₂ (1) (2,5-H₂L¹ = 2,5-dibenzoylterephthalic acid), (Ph₃Sn)₂(2,5-L²)(C₂H₅OH)₂ (2) (2,5-H₂L² = 2,5-bis(4-methylbenzoyl)terephthalic acid), (Ph₃Sn)₂(2,5-L³)(C₂H₅OH)₂ (3) (2,5-H₂L³ = 2,5-bis(4-ethylbenzoyl)terephthalic acid), [(n-Bu₂Sn)₄(4,6-L¹)O₂(OH)(OC₂H₅)]₂·2(C₂H₅OH) (4) (4,6- H₂L¹ = 4,6-dibenzoylisophthalic acid), [(n-Bu₂Sn)₄(4,6-L¹)O₂(OH)(OC₄H₉)]₂·2(C₄H₉OH) (5) and [(n-Bu₂Sn)₄(4,6-L²)O₂(OH)(OC₂H₅)]₂·2(C₂H₅OH) (6) (4,6-H₂L² = 4,6-bis(4-methylbenzoyl)isophthalic acid), have been synthesized. All the organotin carboxylates have been characterized by elemental analysis, IR, ¹H and ¹³C NMR spectroscopy and X-ray crystallography diffraction analyses. The structural analysis reveals that complexes 1-3 show similar structures, containing binuclear triorganotin skeletons. The significant intermolecular O-H?O hydrogen bonds linked the complexes 1-3 to form a novel 2D network polymer with 38-member macrocycles. In complexes 4-6, two Sn₄O₄ ladders are connected by two 1,3-benzenedicarboxylic acid derivatives to yield ladder-like octanuclear architectures and form macrocycle with 24 atoms. In addition, the antitumor activities of complexes 1-6 have been studied.     

Synthesis and structure determination from powder data of the first organically templated tin(IV) phosphate: MIL-76 or Sn3(IV)O2(H2O)(HPO4)4 x [H2N-C2H4-NH2]2.5 x [H2O]2

The first organically templated tin(IV) phosphate has been isolated and its structure solved from powder X-ray diffraction data; it exhibits a one-dimensional inorganic network built up from chains of trimers of tin(IV) octahedra on which phosphate tetrahedral groups are grafted interacting with water molecules and organic moieties.