Syntheses and characterization of triorganotin complexes: X-ray crystallographic study of triorganotin pyridinedicarboxylates with trinuclear, 1D polymeric chain and 2D network structures

A series of new triorganotin(IV) pyridinedicarboxylates [(C₂H₅)₃NH][(Me₃Sn)₃(2,6-pdc)₂(H₂O)₂] (1), [(C₂H₅)₃NH][(Ph₃Sn)₃(2,6-pdc)₂(H₂O)₂] (2), [(C₂H₅)₃NH]{[(PhCH₂)₃Sn]₃(2,6-pdc)₂(H₂O)₂} (3), [Me₃Sn(3,5-pdc)]_n (4), [Ph₃Sn(3,5-pdc)]_n (5), [(PhCH₂)₃Sn(3,5-pdc)]_n (6), [(Me₃Sn)₂(2,5-pdc)]_n (7), [(Ph₃Sn)₂(2,5-pdc)]_n (8) and {[(PhCH₂)₃Sn]₂(2,5-pdc)}_n (9) were synthesized by the reaction of trimethyltin(IV), triphenyltin(IV) or tribenzyltin(IV) chloride with 2,6(3,5 or 2,5)-H₂pdc (pdc = pyridinedicarboxylate) when triethylamine was added. Complexes 1-9 have been characterized by elemental, IR, ¹H, ¹³C and ¹¹⁹Sn NMR analyses. Among them complexes 1, 5 and 7 have also been characterized by X-ray crystallographic diffraction analyses. Complex 1 has a trinuclear structure and forms a 2D supramolecular structure due to the coordinated water molecules via hydrogen bonds to the pendant O atoms of the carboxyl groups and the N atoms derived of the pyridine ring. Complex 5 forms a 1D polymeric chain by the intermolecular Sn?N (N atom derived of pyridine ring) interactions. Complex 7 has a network structure where 2,5-pyridinedicarboxylate acts as a tetradentate ligand coordinated to trimethyltin(IV) ions.     

Synthesis and characterization of some organo-all-tin dendrimers with different peripheral substituents

The synthesis of the first all-tin-dendrimer Sn[(CH₂)₄SnPh₃]₄ (2) results from complete hydrostannation of tetra(but-3-enyl)stannane (1) with triphenyltin hydride. Selective cleavage of one phenyl group from each dendron of 2 with anhydrous HCl results in Sn[(CH₂)₄Sn(Cl)Ph₂]₄ (3), which on treatment with LiAlH₄ yields the corresponding hydride derivative Sn[(CH₂)₄Sn(H)Ph₂]₄ (4) containing four reactive Sn-H bonds. The cyclopentadienyl derivative Sn[(CH₂)₄Sn(C₅H₅)Ph₂]₄ (5) as well as the transition metal substituted derivatives Sn[(CH₂)₄Sn{Co(CO)₄}Ph₂]₄ (6), Sn[(CH₂)₄Sn{Fe(CO)₂C₅H₅}Ph₂]₄ (7), and Sn[(CH₂)₄Sn{Mn(CO)₅}Ph₂]₄ (8) have been prepared by coupling of 3 with the appropriate Grignard or sodium derivatives of the transition metal moieties. The new compounds were characterized by elemental analyses, IR, ¹H-, ¹³C- and ¹¹⁹Sn NMR spectroscopy and MALDI-TOF mass spectrometry.     

Self-assembly of triorganotin(IV) or diorganotin(IV) moieties and 2-methylpyrazine-5-acid: Syntheses, characterizations and crystal structures of monomeric, polymeric or tetranuclear macrocyclic compounds

A series of diorganotin(IV) and triorganotin(IV) compounds of the type [R₂Sn(pca)₂ClSnR₃]₂ (RPhCH₂1, 2-ClC₆H₄CH₂2, 2-FC₆H₄CH₂3, 4-FC₆H₄CH₂4, 4-CNC₆H₄CH₂5, 4-ClC₆H₄CH₂6, 2,4-Cl₂C₆H₃CH₂7; Hpca2-methylpyrazine-5-acid), [(ⁿBu)₃Sn(pca)]_∞8, [(CH₃)₂Cl₂Sn(pca)Sn(CH₃)₂(pca)]_∞9, {[(ⁿBu)₂Sn(pca)]₂O}₂10 and {[Ph₂Sn(pca)]₃O₂[Ph₂Sn(OCH₃)]} 11 have been obtained by reactions of 2-methylpyrazine-5-acid with triorganotin(IV) chloride, diorganotin(IV) dichloride, and diorganotin(IV) oxide. All compounds were characterized by elemental, IR, and NMR spectra analyses. The crystal structure of compounds 1, 8-11 were determined by X-ray single crystal diffraction, which revealed that compound 1 was tetranuclear macrocyclic structures with seven-coordinate and five-coordinate tin atoms, compounds 8 and 9 were polymeric chain structures with five-coordinate and seven-coordinate tin atoms, compounds 10 and 11 were monomeric structures with six-coordinate and five-coordinate tin atoms.     

Synthesis, characterization and structural studies of diorganotin(IV) complexes with Schiff base ligand salicylaldehyde isonicotinylhydrazone

Eight diorganotin(IV) complexes of salicylaldehyde isonicotinylhydrazone (H₂SalN) R₂Sn(SalN) R = t-Bu 1, Ph 2, PhCH₂3, o-ClC₆H₄CH₂4, p-ClC₆H₄CH₂5,m-ClC₆H₄CH₂6,o-FPhCH₂7, p-FC₆H₄CH₂8 were prepared. All complexes 1-8 have been characterized by elemental, IR, ¹H, ¹³C and ¹¹⁹Sn NMR analyses. The crystal structures of H₂SalN and complex 1 were determined by X-ray crystallography diffraction analyses. Studies show that H₂SalN is a tridentate planar ligand. For complex 1, the tin atom lies in this plane and forms a five- and six-membered chelate ring with the tridentate ligand. A comparison of the IR spectra of the ligand with those of the corresponding complexes, reveals that the disappearance of the bands assigned to carbonyl unambiguously confirms that the ligand coordinate with the tin in the enol form.     

Exploring organic reactions using simple cyclodiphosphazanes

Phosphine-activated reactions of alkynes/alkenes/allenes as well as the Mitsunobu reaction involve a rich phosphorus chemistry. With the aid of simple cyclodiphosphazanes, characterization of many compounds analogous to the proposed intermediates in such reactions has been accomplished. Use of a cyclodiphosphazane in Pd-catalyzed N-arylation reactions is highlighted. Results on molecular non-stoichiometry in phosphorus compounds and on the use of chiral phosphorus systems are discussed. Synthesis of allenylphosphoramides involving a cyclodiphosphazane is also described. X-ray structures of the new compounds [(t-BuNH)(PhCH₂CH(CN)CH₂-)P(μ-N-t-Bu)₂P(NH-t-Bu)]⁺[HCO₃]⁻ (13), [(t-BuNH)P(μ-N-t-Bu)₂P(N-t-Bu)-C(CH₂)CH(C₆H₄-4-Me)-P(O)(OCH₂CMe₂CH₂O)] (18), [(i-PrNH)P(μ-N-t-Bu)₂P(N-i-Pr)-N(CO₂-i-Pr)-NH(CO₂-i-Pr)] (24), [(S)-(2-OH-1-C₁₀H₆-1′-C₁₀H₆-2′-O-P(O)(NH-t-Bu)₂] (36) and [(t-BuNH)(O)P(μ-N-t-Bu)₂P(O)(CHCCMe₂)] (40) are also reported.     

Synthesis and structural characterization of organotin(IV) compounds derived from the self-assembly of hydrazone Schiff base series and various alkyltin salts

Reactions of pyruvic acid hydrazone series [pyruvic acid thiophenecarbonyl hydrazone (L1), pyruvic acid 4-hydroxybenzoylhydrazone (L2), pyruvic acid salicyloylhydrazone (L3), pyruvic acid benzoylhydrazone (L4)], or salicylaldehyde hydrazone Schiff base ligand [salicylaldehyde isonicotinoylhydrazone (L5)] with different alkyltin salts result in six new organotin(IV) compounds, {(n-Bu)₂Sn[2-SC₄H₃CON₂C(CH₃)CO₂](HOC₃H₇-i)}₂ (1), [{(n-Bu)₂SnCl(O)(n-Bu)₂ Sn(O)[C₆H₄CON₂C(CH₃)CO₂]Sn(n-Bu)₂(HOCH₃)}₂]_∞ (2), {(o-ClBz)₂Sn[4-HOC₆H₄CON₂C(CH₃) CO₂] (HOC₂H₅)}₂ (3), {(n-C₈H₁₇)₂Sn[2-HOC₆H₄CON₂C(CH₃)CO₂](H₂O)}₂ (4), {(n-Bu)₂Sn[C₆H₅ CON₂C(CH₃)CO₂][HOSn(n-Bu)₃]}₂ (5), and {[(n-C₄H₉)SnCl₂]⁻[4-NHC₅H₄CON₂CH (C₆H₄O-2)]⁺ (6), which have been characterized by single crystal X-ray diffraction, elemental analysis, IR, ¹H and ¹¹⁹Sn NMR. In compounds 1, 3, 4, weak-bridged dimers are found, in which the two tin atoms are linked by a pair of monodentate bridges. Each pyruvic acid hydrazone ligand serves as an enolic tridentatic ligand. Compound 2 contains dimeric units of {Sn₆(L2)₂(n-Bu)₆(HOCH₃)₂} that are further connected by two pairs of monodentate bridges into an 1D weak-bridged polymeric chain, in which there also exists a fascinating dichlorodistannoxane ladder structure. Studies show that the bulk and steric hindrance of the alkyl groups and the coordinated solvent molecule bonding to Sn center have little effect on the geometry of the weak-bridge for compounds 1-4. A similar weak-bridged dimeric structure is also found in compound 5; in this case, however, there is no coordinated solvent molecule and the corresponding coordination site is replaced by the trialkyltin hydroxide. Compound 6 exhibits a rare 1D supermolecular chain constructed from the zwitterionic {Sn(L5)(n-Bu)Cl₂} units connected by the intermolecular N-H?Cl hydrogen bonds. The thermal stability of compound 1 was also studied.     

Syntheses and crystal structures of four new organotin complexes with Schiff bases containing triazole

Four new organotin complexes, namely [(Bu₂Sn)₂O(EtO)(L1)]₂ (1), [(Bu₂Sn)₂O(EtO)(L2)]₂ (2), [(Bu₂Sn)₂O(EtO)(L3)]₂ (3) and [Ph₃Sn(L4)] · 0.5H₂O (4), were obtained by reactions of Bu₂SnO and Ph₃SnOH with 4-phenylideneamino-3-methyl-1,2,4-triazole-5-thione (HL1), 4-furfuralideneamino-3-methyl-1,2,4-triazole-5-thione (HL2), 4-(2-thienylideneamino)-3-ethyl-1,2,4 -triazole-5-thione (HL3) and 4-(3,5-di-t-butylsalicylideneamino)-3-ethyl-1,2,4-triazole-5-thione (HL4). Compounds 1-4 were characterized by elemental analysis, IR spectra and their structures were determined by single-crystal X-ray diffraction methods. Complexes 1-3 show similar structures containing a Sn₄O₄ ladder skeleton in which each of the exo tin atoms is bonded to the N atom of a corresponding thione-form deprotonated ligand. Complex 4 shows a mononuclear structure in which the tin atom of triphenyltin group is coordinated by the S atom of a thiol-form L4⁻ anion.     

Synthesis, structural characterization and electrochemistry of C,N-chelated organotin(IV) dicarboxylates with ferrocenyl substituents

A set of C,N-chelated organotin(IV) ferrocenecarboxylates, [L^CN(n-Bu)Sn(O₂CFc)₂] (1), [(L^CN)₂Sn(O₂CFc)₂] (2), [L^CN(n-Bu)Sn(O₂CCH₂Fc)₂] (3), [L^CN(n-Bu)Sn(O₂CCH₂CH₂Fc)₂] (4), [L^CN(n-Bu)Sn(O₂CCHCHFc)₂] (5), [L^CN(n-Bu)Sn(O₂CfcPPh₂)₂] (6), [(L^CN)₂Sn(O₂CfcPPh₂)₂] (7), and [L^CN(n-Bu)₂Sn(O₂CFc)] (8) (L^CN = 2-(N,N-dimethylaminomethyl)phenyl, Fc = ferrocenyl and fc = ferrocene-1,1′-diyl) has been synthesized by metathesis of the respective organotin(IV) halides and carboxylate potassium salts and characterized by multinuclear NMR and IR spectroscopy. The spectral data indicated that the tin atoms in diorganotin(IV) dicarboxylates bearing one C,N-chelating ligand (1 and 3-6) are seven-coordinated with a distorted pentagonal bipyramidal environment around the tin constituted by the n-butyl group, the chelating L^CN ligand and bidentate carboxylate. Compounds 2 and 7 possessing two chelating L^CN ligands comprise octahedrally coordinated tin atoms and monodentate carboxylate donors, whereas compound 8 assumes a distorted trigonal bipyramidal geometry around tin with the carboxylate binding in unidentate fashion. The solid state structures determined for 1⋅C₆D₆ and 2 by single-crystal X-ray diffraction analysis are in agreement with spectroscopic data. Compounds 1, 3-5, and 8 were further studied by electrochemical methods. Whereas the oxidations of ferrocene units in bis(carboxylate) 2 and monocarboxylate 8 proceed in single steps, compound 1 undergoes two closely spaced one-electron redox waves due to two independently oxidized ferrocenyl groups. The spaced analogues of 2, compounds 3-5, again display only single waves corresponding to two-electron exchanged.     

Investigation on coordination modes of organotin(IV) complexes with 6-thiopurine and related ligands

The organotin(IV) complexes R₂Sn(tpu)₂ · L [L = 2MeOH, R = Me (1); L = 0: R = n-Bu (2), Ph (3), PhCH₂ (4)], R₃Sn(Hthpu) [R = Me (5), n-Bu (6), Ph (7), PhCH₂ (8)] and (R₂SnCl)₂ (dtpu) · L [L = H₂O, R = Me (9); L = 0: R = n-Bu (10), Ph (11), PhCH₂ (12)] have been synthesized, where tpu, Hthpu and dtpu are the anions of 6-thiopurine (Htpu), 2-thio-6-hydroxypurine (H₂thpu) and 2,6-dithiopurine (H₂dtpu), respectively. All the complexes 1-12 have been characterized by elemental, IR, ¹H, ¹³C and ¹¹⁹Sn NMR spectra analyses. And complexes 1, 2, 7 and 9 have also been determined by X-ray crystallography, complexes 1 and 2 are both six-coordinated with R₂Sn coordinated to the thiol/thione S and heterocyclic N atoms but the coordination modes differed. As for complex 7 and 9, the geometries of Sn atoms are distorted trigonal bipyramidal. Moreover, the packing of complexes 1, 2, 7 and 9 are stabilized by the hydrogen bonding and weak interactions.     

The reaction of the group-13 alkyls ER3 (E = Al, Ga, In; R = CH2t-Bu, CH2 SiMe3) with the platinum-complex [(dcpe)Pt(H)(CH2t-Bu)]

The reactions of the sterically demanding group-13 alkyls ER₃ (E = Al, Ga, In; R = CH₂t-Bu, CH₂SiMe₃) with the platinum-complex [(dcpe)Pt(H)(CH₂t-Bu)] were re-investigated. The bimetallic compounds [(dcpe)Pt(ER₂)(R)] (3: E = Ga, R = CH₂SiMe₃; 5: E = In, R = CH₂t-Bu; dcpe = bis(dicyclohexylphosphino)ethane) with direct σ(Pt-E) bonds were obtained by oxidative addition of an E-C bond to the coordinatively unsaturated fragment [(dcpe)Pt] produced in situ by thermolysis of the starting complex [(dcpe)Pt(CH₂t-Bu)(H)]. The single crystal structure determination reveals a Pt-Ga bond length of 2.376(2) Å and a Pt-In bond length of 2.608(1) Å. All new compounds were characterised by elemental analysis, ³¹P and ¹⁹⁵Pt NMR spectroscopy. Interestingly, the Pt-Ga compound 3 slowly transforms into the platinum alkyl/hydride isomer {(dcpe)Pt(μ₂-H)[CH₂Si(CH₃)₂ CH₂Ga(CH₂SiMe₃)₂]} (4) during crystallization from solution at room temperature. The X-ray single crystal structure analysis revealed both complexes 3 and 4 coexisting in the unit cell in a 1:1 relation. The inaccessibility of analytically pure samples of the Pt-Al complex {(dcpe)Pt[Al(CH₂t-Bu)₂](CH₂t-Bu)} (6), postulated as intermediate of the reaction of [(dcpe)Pt(H)(CH₂t-Bu)] with Al(CH₂t-Bu) on the basis of ³¹P and ¹⁹⁵Pt NMR data, is attributed to an enhanced tendency to isomerisation into the alkyl/hydride Pt/Al congener of 4. A brief DFT analysis of the bonding situation of the model complex [(dhpe)Pt(GaMe₂)(Me)] (1M) revealed, that the contribution of π(Pt-Ga) back-bonding is negligible.     

Reactions of [η-carboxycyclopentadiene][η-tetraphenylcyclo butadiene] cobalt with alkyl and aryl tin oxides: Synthesis, structural studies and electrochemistry of novel monomeric and dimeric [η-carboxycyclopentadiene][η-tetraphenylcyclobutadiene]cobalt based stannoxanes

Reactions of [η⁵-carboxycyclopentadienyl][η⁴-tetraphenylcyclobutadiene] cobalt, Ph₄C₄CoC₅H₄COOH (1), with (Ph₃Sn)₂O, [(n-Bu)₂SnO]_n and (Ph₂SnO)_n in refluxing toluene resulted in the formation of the monomeric compound Ph₃SnOC(O)C₅H₄CoC₄Ph₄ (2) and dimeric compounds n-Bu₂Sn[OC(O)C₅H₄CoC₄Ph₄]₂ (3) and Ph₂Sn[OC(O)C₅H₄CoC₄Ph₄]₂ (4), respectively. Reactions carried out in the solid state by mechanical grinding also yielded same results. Crystal structure determination and cyclic voltammetric studies of compounds 1, 2, 3 and 4 have been carried out and compared with similar ferrocene carboxylic acid derivatives. The structures and electrochemistry of these compounds are compared with analogous organotin ferrocene carboxylates. The results obtained from the reaction of 1 with alkyl and aryl tin oxides suggest that the formation of stannoxanes assemblies having more than two carboxylate units are not favored indicating that 1 is a highly sterically hindered metallocene carboxylic acid.     

Structural diversity of di and triorganotin complexes with 4-sulfanylbenzoic acid: Supramolecular structures involving intermolecular Sn?O, O-H?O or C-H?X (X = O or S) interactions

Twelve new organotin complexes with 4-sulfanylbenzoic acid of two types: R_nSn[S(C₆H₄COOH)]_4−n (I) (n = 3: R = Me 1, n-Bu 2, Ph 3; PhCH₂4; n = 2: R = Me 5; n-Bu 6, Ph 7, PhCH₂8) and R₃Sn(SC₆H₄COO)SnR₃ · mEtOH (II) (m = 0: R = Me 9, n-Bu 10, PhCH₂12; m = 2: R = Ph 11), along with the 4,4′-bipy adduct of 9, [Me₃Sn(SC₆H₄COO)SnMe₃]₂(4,4-bipy) 13, have been synthesized. The coordination behavior of 4-sulfanylbenzoic acid is monodentate in 1-8 by thiol S atom but not carboxylic oxygen atom. While, in 9-13 it behaves as multidenate by both thiol S atom and carboxylic oxygen atoms. The supramolecular structures of 6, 11 and 13 have been found to consist of 1D molecular chains built up by intermolecular O-H?O, C-H?O or C-H?S hydrogen bonds. The supramolecular aggregation of 7 is 2D network determined by two C-H?O hydrogen bonds. Extended intermolecular C-H?O interactions in the crystal lattice of 9 link the molecules into a 2D network.     

Synthesis, structures and preliminary biological screening of bis(diphenyl)chlorotin complexes and adducts: Ph2ClSn-CH2-R-CH2-SnClPh2, R = p-C6H4, CH2CH2

The reaction between ClCH₂-R-CH₂Cl, R = p-C₆H₄, and [Ph₃Sn]⁻Li⁺ yields Ph₃Sn-CH₂-R-CH₂-SnPh₃ (1) in high yield. The related known compound R = CH₂CH₂ (1a) is synthesized by the reaction of the di-Grignard reagent BrMg(CH₂)₄MgBr with two equivalents of Ph₃SnCl. Cleavage of a single Sn-Ph group at each tin centre of both compounds using HCl/Et₂O yields the corresponding bis-chlorostannanes Ph₂ClSn-CH₂-R-CH₂-SnClPh₂, R = (CH₂)₄ (2) and R = C₆H₄ (3), respectively. Compounds 1, 2 and 3 are crystalline solid materials and their single crystal X-ray structures are reported. In the solid state both 2 and 3 form self-assembled ladder structures involving alternating intermolecular Cl-Sn?Cl and Cl?Sn-Cl bonded chains at both ends of the distannanes with 5-coordinate tin atoms. Recrystallization of 3 from CH₂Cl₂ in the presence of DMF yields the bis-DMF adduct (4) in which no self-assembled structures were noted. Evaluation of the chlorostannanes 2 and 3 against a suite of bacteria, Staphylococcus aureus, Escherichia coli and Photobacterium phosphoreum is reported and compared to the related mono-chlorostannanes Ph₂(CH₃)SnCl and Ph₂(PhCH₂)SnCl.     

Syntheses, crystal structures and coordination modes of tri- and di-organotin derivatives with 2-mercapto-4-methylpyrimidine

The organotin (IV) derivatives of 2-mercapto-4-methylpyrimidine (Hmpymt) R₃SnL (R = Ph 1, PhCH₂2, n-Bu 3), R₂SnCl_mL_n (m = 1, n = 1, R = CH₃4, Ph 5, n-Bu 6, PhCH₂7; m = 0, n = 2, R = CH₃8, n-Bu 9, Ph 10, PhCH₂11) were obtained by the reaction of the organotin(IV) chlorides R₃SnCl or R₂SnCl₂ with 2-mercapto-4-methylpyrimidine hydrochloride (HCl · Hmpymt) in 1:1 or 1:2 molar ratio. All complexes 1-11 were characterized by elemental analyses, IR, ¹H, ¹³C and temperature-dependent ¹¹⁹Sn NMR spectra. Except for complexes 3 and 6, the structures of complexes 1, 2, 4, 5, 7, 8-11 were confirmed by X-ray crystallography. Including tin-nitrogen intramolecular interaction, the tin atoms of complexes 1-7 are all five-coordinated and their geometries are distorted trigonal bipyramidal. While the tin atoms of complexes 8-11 are six-coordinated and their geometries are distorted octahedral. Besides, the ligand adopts the different coordination modes to bond to tin atom between the complexes 1, 6, 7 and 2, 3, 4, 5, 8-11. Furthermore, intermolecular Sn?N or Sn?S interactions were recognized in crystal structures of complexes 4, 7 and 11, respectively.     

Chiral organotin (IV) carboxylates complexes: Syntheses, characterization, and crystal structures with chiral (S)-(+)-6-methoxy-α-methyl-2-naphthaleneaceto acid ligand

Eight new organotin (IV) carboxylates, (R₃Sn)₄(nap)₄ (R = Me 1, n-Bu 2), [(R₃Sn) (nap)]_n (R = Ph 3, PhCH₂4), (R₂Sn) (nap)₂ (R = n-Bu 5, Ph 6, PhCH₂7) and {[R₂Sn(nap)]₂O}₂ (R = Me 8) (nap = (S)-(+)-6-methoxy-α-methyl-2-naphthaleneaceto anion) have been synthesized. All of the complexes have been characterized by elemental analysis, FT-IR, NMR (¹H, ¹³C and ¹¹⁹Sn) spectra. Among these complexes, complexes 1, 3, 5 and 8 were also characterized by X-ray crystallography diffraction analysis, and the data of X-ray crystallography diffraction indicated that complexes 1, 3 and 5 are new chiral organotin (IV) carboxylates complexes. The structural analyses show that complex 1 has a tetranuclear Sn₄O₈ macrocycle structure, complex 3 has a 1D spring-like chiral helical chain with a columnar channel, complex 5 possesses a dimer structure, and complex 8 has a supramolecular chainlike ladder structure through weak intermolecular non-covalent O^…O interactions.     

Syntheses, characterization and crystal structures of di- and triorganotin (IV) derivatives with 6-amino-1,3,5-triazine-2,4-dithiol

A series of organotin (IV) complexes with 6-amino-1,3,5-triazine-2,4-dithiol of the type [(R_nSnCl_4−n)₂ (C₃H₂N₄S₂)] (n = 3: R = Me 1, n-Bu 2, PhCH₂3, Ph 4; n = 2: R = Me 5, n-Bu 6, PhCH₂7, Ph 8) have been synthesized. All the complexes 1-8 have been characterized by elemental analysis, IR, ¹H and ¹³C NMR spectra. Among them complexes 1, 4, 5 and 8 have also been characterized by X-ray crystallography diffraction analyses, which revealed that the tin atoms of complexes 1, 4, 5 and 8 are all five-coordinated with distorted trigonal bipyramid geometries.     

Synthesis and structural characterization of diorganotin(IV) esters with pyruvic acid isonicotinyl hydrazone and pyruvic acid salicylhydrazone Schiff bases

Eight diorganotin esters of Schiff base ligands formulated as [R₂SnLY]₂, where L₁ is 4-NC₅H₄CON₂C(CH₃) CO₂ with Y = H₂O, R = Ph (1), PhCH₂ (2), m-ClC₆H₄CH₂ (3), and L₂ is 2-HOC₆H₄CON₂C(CH₃) CO₂ with Y = CH₃OH, R = PhCH₂ (4), o-ClC₆H₄CH₂ (5), m-ClC₆H₄CH₂ (6), o-FC₆H₄CH₂ (7), p-FC₆H₄CH₂ (8) have been prepared and characterized by elemental analysis, IR, ¹H and ¹¹⁹Sn NMR spectra. The crystal structures of compounds 1, 2 and 4 have been determined by X-ray single crystal diffraction. Their structures show that the tin atoms of three compounds are all rendered seven-coordinated in distorted pentagonal bipyramid geometries with a planar SnO₄N unit and two apical aryl carbon atoms. A comparison of the IR spectra of the ligands with those of the corresponding compounds, reveals that the disappearance of the bands assigned to carbonyl unambiguously conforms that the ligands coordinate with tin in the enol form.     

Syntheses and crystal structures of diorganotin (IV) moieties with 3-hydroxy-2-pyridinecarboxylic acid

A series of new organotin (IV) complexes with 3-hydroxy-2-pyridinecarboxylic acid (3-OH-2-picH) of two types: R₂SnCl(3-OH-2-pic) (I) (R = Me 1, n-Bu 2, Ph 3, PhCH₂4) and R₂ Sn(3-OH-2-pic)₂ (II) (R = Me 5, n-Bu 6, Ph 7, PhCH₂8)have been synthesized by reactions of diorganotin (IV) dichloride with 3-hydroxy-2-pyridinecarboxylic acid in the presence of sodium ethoxide. All complexes are characterized by elemental analyses, IR spectra and NMR spectra analyses. Among them, complexes 1, 5, 6 and 7 are also characterized by X-ray crystallography diffraction analyses. Complex 1 is a 1D polymeric chain with six-coordinate tin atoms and the packing of complex 1 is stabilized by the C-H?Cl intermolecular weak interactions, thus a 2D network of 1 is formed. Complex 5 is also a 1D polymeric chain with seven-coordinate tin atoms. Complex 6 is a zigzag polymeric chain linked by Sn?O intermolecular weak interactions. Complex 7 is a monomeric complex with distorted octahedral geometry.     

Syntheses, characterizations and crystal structures of triorganotin(IV) derivatives with 2-mercapto-4-quinazolinone

The triorganotin(IV) derivatives of 2-mercapto-4-quinazolinone (HSqualone) of the type, R₃SnL (R = Ph 1, CH₃2, PhCH₂3, p-F-PhCH₂4, o-F-PhCH₂5, n-Bu 6), were obtained by the reaction of the R₃SnCl and HSqualone with 1:1 molar ratio in benzene. All complexes 1-6 were characterized by elemental analyses, IR, ¹H and ¹³C NMR spectroscopy and the crystal structures of complexes 1-3 were also confirmed by X-ray crystallography. The structure analyses reveal that the tin atoms of complexes 1-3 are all distorted tetrahedral geometries. Furthermore, the dimeric structures in complexes 1-3 have also been found linked by intermolecular O-H?N or N-H?O hydrogen bonding interaction. Interestingly, the dimers of complexes 2 and 3 are further linked into one-dimensional chain through intermolecular C-H?S and C-H?O weak hydrogen bonding interactions, respectively.     

Synthesis and spectroscopic properties of [N-(4-carboxyphenyl) salicylideneiminato] di- and tri-organotin (IV) complexes and crystal structures of {[Bu2Sn(2-OHC6H4CHNC6H4COO)]2O}2 and Ph3Sn(2-OHC6H4CHNC6H4COO)

Reactions of R₂SnO (R: ⁿBu, Cy, Ph, PhCH₂) and R₃SnCl (R: Ph, Cy, PhCH₂, 2-Cl-PhCH₂, 4-F-PhCH₂, 4-Cl-PhCH₂) with N-(4-carboxyphenyl)-salicylideneimine (LH₂) in 1:1 stoichiometry afford complexes {[R₂Sn(LH)]₂O}₂ and R₃Sn(LH). These complexes have been characterized by elemental analyses, IR, ¹H and ¹¹⁹Sn NMR spectroscopy. The crystal structures of {[ⁿBu₂Sn(LH)]₂O}₂, 1 and Ph₃Sn(L), 5 are determined by single crystal X-ray diffraction. Results showed that in the solid state the complex 1 is a tetranuclear centrosymmetric dimer with six-coordination being assigned to both the endo-cyclic and exo-cyclic tin atoms after consideration of close intermolecular tin oxygen contacts, and study show that the imino nitrogen atom do not participate in coordination to the tin atom. The complex 5 is a monomer, and in the molecule the tin atoms are five-coordinated in trigonal bipyramidal geometries with the two oxygen atom of the carboxylate both coordinating to the tin atoms.