Search

• Chemistry of benzo[c]telluropyran (2-telluranaphthalene). • Chemistry of benzo[c]stibinine (2-stibanaphthalene). • Chemistry of benzo[c]stannine (2-stannanaphthalene). • Chemistry of benzo[ c ] germine (2-germanaphthalene). • Application of 2-metallanaphthalenes. The fusion of benzene with the c edge of 4 H -telluropyran, 4 H -stanine, 4 H -stibinine or 4 H -germine 2d motifs in hybrid configurations forms four distinct structures: condensed 2-telluranaphthalene, 2-stibanaphthalene, 2-stannanaphthalene and 2-germanaphthalene (2-metallanaphthalenes). 2-Metallanaphthalene (Metal= Te, Sb, Sn and Ge) is characterized by the presence of a Te, Sb, Sn and Ge atom in the second position instead of the first of 2-metallanaphthalene. To our knowledge, no reports have been published specifically on this scaffold, which has primarily been used as a building block. The synthesis of 2-telluranaphthalene, 2-stibanaphthalene, 2-stannanaphthalene or 2-germanaphthalene and their analogues can be achieved through various chemical pathways, including the Sonogashira coupling reactions, nucleophilic addition, organometallic reactions, metal substitution, and other methods. This review aims to offer a meticulous and all-encompassing analysis of the synthesis techniques and chemical reactivity of 1 H -benzo[c]telluropyran, 1 H -benzo[c]stannine, 1 H -benzo[c]stibinine, and 1 H -benzo[c]germine. [Display omitted] [ABSTRACT FROM AUTHOR]

• Synergy of Lewis acids and silanols in Sn- and Ti-Beta was investigated by DRIFTS. • Double bond migration of n -butene to cis -2-butene followed AB–AD mechanism. • The isomerization between cis -2-butene and trans -2-butene followed AD–AB mechanism. • Reaction mechanisms of butenes depended on methyl or methylene groups. The synergistic effect of Lewis acidic Sn/Ti sites and silanols in Sn- and Ti-Beta zeolites on the reaction pathways and mechanisms of the conversion of butenes was investigated by in situ diffuse reflectance infrared Fourier transform spectroscopy. The double bond migration reaction of n -butene to cis -2-butene followed an AB–AD mechanism, in which hydrogen abstraction (AB) from the methylene group at Lewis acidic Sn/Ti sites afforded an allyl intermediate, followed by synergistic hydrogen addition (AD) on silanols. In contrast, the following cis – trans isomerization reaction between cis -2-butene and trans -2-butene, and the activation of isobutene, followed an AD–AB mechanism via hydrogen addition to the double bond of butenes on silanols, forming an alkoxyl group rather than allyl group as the intermediate owing to the absence of a methylene group in 2-butene and isobutene. [Display omitted] [ABSTRACT FROM AUTHOR]

• 8-Hydroxyquinoline-based tin(IV) complexes have been synthesized and characterized. • Photophysical studies have been carried out in solvents of varying polarity. • All complexes show high fluorescence quantum yield apart from displaying longer lifetimes. • DFT calculations support the observed electronic and structural properties. Four different 8-hydroxyquinoline derivative-based tin(IV) complexes [(n Bu) 2 Sn(Cl-Q-CHO) 2 ] (1), [{(n Bu) 4 Sn 2 (Q-COO) 2 } 2 ] (2), [Ph 2 Sn(Cl)(Q-CHO)] (3) and [Ph 2 Sn(Cl)(Q-CH{OMe} 2)] (4) (Cl-Q-CHO = 5‑chloro-8-hydroxyquinolin-7-carbaldehyde; Q-COO− = 8-hydroxyquinolin-2-carboxylate; Q-CHO = 8-hydroxyquinolin-2-carbaldehyde and Q-CH{OMe} 2 = 2-(dimethoxy methyl)quinolin-8-ol) have been synthesized and characterized by elemental analysis, spectroscopy (FT-IR, Mass, UV–Vis, photoluminescence, 1H, 13C and 119Sn NMR) and thermogravimetric analysis. Complexes 1 and 4 have also been characterized by single-crystal diffraction studies and the bulk purity established by powder X-ray diffraction studies. Photophysical studies were conducted in a variety of solvents to demonstrate the effect on excitation and emission on the polarity of the solvent. All the new complexes show higher luminescence in a polar solvent resulting in the stabilization of the excited states. Complex 1 shows a high quantum yield of 97% in chloroform. Further, the photophysical results were substantiated through DFT calculations. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract An acyclic flexible bis(α-iminopyridine) ligand has been employed for the stabilization of chlorostannyliumylidene and a tin(II) dication. The syntheses involve the abstraction of chloride from the tin dichloride precursor using trimethylsilyl trifluoromethane sulfonate. The apically disposed tin(II) dication exhibits electrophilic behaviour and undergoes transmetallation reaction with GeCl 2.dioxane resulting in stabilizing the Ge(II) dication. All the compounds have been characterized by NMR techniques and single crystal X-ray crystallography. Graphical abstract A pyramidal tin(II) dication has been stabilized within an acyclic bis(α-iminopyridine) ligand framework. The apical disposition of the tin(II) dicationic center allows its further reactivity. While the dication is inherently electrophilic, the presence of significant s -character restricts nuclephilicity. The tin(II) diaction undergoes transmetallation with GeCl2.dioxane stabilizing Ge(II) dication. Image 1 Highlights • A Sn(II) dication has been stabilized by bis(α-iminopyridine). • The Sn(II) dicationic site is apically disposed allowing further reactivity. • High s -character of the lone pair on Sn(II) dication prohibits its nucleophilicity. • The Sn(II) dication shows electrophilic behaviour. • The Sn(II) dication undergoes transmetallation reaction with GeCl2.dioxane. [ABSTRACT FROM AUTHOR]

• Three new ferriostannylenes having different tin substituents, ArSnFeCp(CO) 2 (1), ArSnFeCp*(CO) 2 (2), and ArSnFeCp(CO)(PMe 3) (3) were isolated. • Increasing the aryl substituent size causes closure of the interligand angle the tin atom. • Replacement of a CO group with a phosphine causes the interligand angle at the tin atom to widen. A series of ferriostannylenes of formula ArMe6SnFeCp(CO) 2 (ArMe6 = −C 6 H 3 -(C 6 H 2 –2,4,6-Me 3) 2 , Cp = η 5-C 5 H 5) (1), ArMe6SnFeCp*(CO) 2 (Cp* = η 5-C 5 Me 5) (2), and ArMe6SnFeCp(CO)(PMe 3) (3) with differing iron and/or tin substituents was synthesized. Their structures and spectroscopic properties were examined by X-ray crystallography, NMR, IR, and UV–vis spectroscopy and compared with data for related species. The structural data showed that, as the size of the terphenyl substituent increases, the C-Sn-Fe angle decreases slightly which is contrary to steric expectations. The 1H and 119Sn NMR chemical shifts of the least crowded species 1 is similar to, but slightly upfield of those of its more hindered ferriostannylene analogs. Unexpectedly, 3 displayed a 119Sn NMR chemical shift that is ca. 800 ppm downfield of 1 as a result of the substitution of one of the iron carbonyl groups with a PMe 3 ligand. This unusual finding is probably a reflection of a decreased paramagnetic shielding of the 119Sn nucleus by the more electron releasing character of the PMe 3 ligand which decreases the n→p energy gap. The infrared spectrum of 1 also displayed slightly higher ν CO frequencies, and its electronic spectrum indicated a small hypsochromic shift in the energy of its n→p transition whereas both 2 and 3 displayed much greater hypsochromic shifts than 1 consistent with the more electron donating character of the iron phosphine substituent. The results were interpreted in terms of the electronic/steric properties of the various substituents and their effects on metal electron density. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract A series of six new organotin(IV) compounds, namely, [ n Pr 3 Sn(HL)(MeOH)] 1 , [ n Bu 3 Sn(HL)] n 2 , [Bz 3 Sn(HL)] n 3 , [Ph 3 Sn(HL)] n ⋅nC 6 H 6 4 , [Ph 3 Sn(HL)(EtOH)] 5 and [ n Bu 2 Sn(L)] n 6 were synthesized by reacting appropriate tri- and di-organotin(IV) precursors with the flexible pro-ligand 5-[( E )-2-(4-pyridyl)-1-diazenyl]-2-hydroxybenzoic acid. Their solid-state structures were deduced from single crystal X-ray diffraction data and, in the case of compound 6 , also by solid-state 13C and 119Sn NMR spectroscopy. Compounds 1 and 5 are mononuclear as a consequence of methanol/ethanol coordination preventing the propagation of the polymers. The monodentate oxygen atom from the carboxylate group of HL− and the tin-coordinated oxygen atom of alcohol are situated at the axial positions, while Sn-R substituents are at the equatorial sites, defining the distorted trigonal-bipyramidal coordination polyhedron. Both 1 and 5 form one-dimensional (1D) chains created by virtue of O−H solv ⋯N py hydrogen bonding interactions, and antiparallel running chains in 1 furnish 34-membered dinuclear macrocyclic rings occupied by SnPr 3 groups. Compounds 2 – 4 feature a one-dimensional coordination polymer facilitated by intermolecular N→Sn bond formation with the pyridyl substituent of LH−. The axially located O OCO and N py donor atoms and equatorial Sn-R groups give rise to a trigonal-bipyramidal geometry. While similar coordination geometries are observed for 2 – 4 , the tri- n -butyl derivative 2 generates 60-membered macrocyclic rings where four n -butyl groups from two neighboring molecules occupy the cavities. The triphenyltin analogue 4 forms two-dimensional layers with voids filled by benzene solvate molecules, and the sterically demanding tribenzyltin groups in compound 3 result in only relatively weak C−H⋯π, C−H⋯N and van der Waals contacts. On the other hand, compound 6 is a two-dimensional (2D) coordination polymer displaying a distorted pentagonal-bipyramidal geometry around the tin atom where four oxygen atoms of two ligand molecules and the nitrogen atom of a ligand constitute the equatorial plane, while the carbon atoms of the n -butyl groups complete the axial positions. The molecules of 6 self assembled to an interesting dimeric tecton based on a four-membered Sn 2 O 2 ring, generating large 48-membered hexanuclear macrocycles, where the cavities are filled by four di- n -butyl groups from two neighboring molecules. The solution behaviors of compounds 1 – 5 were judged from the results of the 119Sn NMR spectroscopic characterization. Graphical abstract Image 1 Highlights • Six new organotin(IV) compounds have been synthesized. • The coordination pattern at the Sn(IV) center was established by X-ray diffraction. • Mononuclear adducts [R 3 Sn(HL)(solv)] 1 and 5 were obtained when crystallized from alcohol. • Other solvents generated 1D CPs of [R 3 Sn(HL)] n 2 – 4 based on N→Sn bond formation. • Molecules of [ n Bu 2 Sn(L)] n 6 self assembled to a dimeric tecton, generating 48-membered hexanuclear macrocycles. [ABSTRACT FROM AUTHOR]

Two new tin (II) and tin (IV) compounds [LSnCl] ( 1 ) and [LSnCl 3 ] ( 2 ), bearing the β -diketiminato ligand LH (L = HC(CMeNAr) 2 , Ar = 2,6-Et 2 C 6 H 3 ) were synthesized by the reactions of LH with n -BuLi, then respectively with SnCl 2 and SnCl 4 . Two new aluminum alkyl compounds, [LAlMe 2 ] ( 3 ) and [LAlEt 2 ] ( 4 ), were synthesized in high yield from the reactions of LH with AlMe 3 and AlEt 2 , respectively. Compound [LAlI 2 ] ( 5 ) was synthesized from the reaction of 3 with I 2 in good yield. All these main group metal compounds bearing β -diketiminato ligand LH were fully characterized by 1 H NMR and 13 C NMR spectroscopy, and elemental analysis. Meanwhile, compounds 1 , 2 , 3 , and 5 were characterized by single crystal X-ray structural analysis. Moreover, the well-defined compounds 1 – 4 were investigated to show good catalytic activity in hydroboration of terminal alkynes. [ABSTRACT FROM AUTHOR]

The syntheses, spectroscopic data and crystal structures of (H 2 NCOCH 2 CH 2 - C )(R 2 NCS 2 - S,S ′ ) 3 Sn ( 1 ), (H 2 NCOCH 2 CH 2 - C,O ) 2 SnCl 2 (triclinic polymorph) ( 2 ), (H 2 NCOCH 2 CH 2 - C,O) (2-H 2 NCOC 6 H 4 S- O,S )SnCl 2 ( 3 ) and Sn(C 11 H 9 N 2 O 2 )Cl 3 ( 4 ) are reported. The tin atom in compound 1 (R = Et) is coordinated by three chelating dithiocarbamate anions and a C-bound non-chelating amidoethyl ligand to generate a SnS 6 C pentagonal-bipyramidal coordination polyhedron. Compound 2 , which features SnC 2 O 2 Cl 2 octahedra, was crystallised from mixed solvents (ethanol and water) and complements the two known monoclinic forms. Compound 3 arose unexpectedly due to ligand disproportionation of the tin starting material and a “ trans -esterification” reaction of the starting ligand: distorted SnCSO 2 Cl 2 octahedra are seen in the crystal structure. Compound 4 arose from another ligand disproportionation reaction and features neutral complex molecules with N 2 OCl 3 donor sets coordinating to the octahedral tin atoms. [ABSTRACT FROM AUTHOR]

Transition metal complexes containing the sterically encumbered SnBu t 3 group are the focus of this brief review. The ability of tin compounds to modify both heterogeneous and homogeneous catalysts has been known for some time. Our recent efforts center on utilizing the reagent Bu t 3 SnH to investigate the influence of this ligand, which combines a steric profile similar to that of PBu t 3 , with functional reactivity at the Sn-H bond. These properties of the SnBu t 3 ligand allow preparation of new complexes and comparison of their structures and reactivities with less encumbered trialkyl stannanes. This has allowed fine-tuning of the strained molecular geometry at the coordinatively unsaturated site and study of how that influences small molecule activation. Reversible H 2 binding and activation, H 2 –D 2 scrambling to form HD, C-H activation of bound ligands and solvents, catalytic hydrogenation, and catalytic hydrostannylation have all been observed for select complexes. In addition, a range of metal cluster complexes incorporating stannane moieties have been prepared and structurally characterized. The Bu t 3 SnH ligand provides a new dimension for preparation of new molecular architectures with potential applications in homogeneous and heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

Six new bicycloazastannoxides of compositions [Me 2 Sn(L 1 H)] ( 1 ), [ n Bu 2 Sn(L 1 H)] ( 2 ), [Ph 2 Sn(L 1 H)] ( 3 ), [Bz 2 Sn(L 1 H)] ( 4 ), [Me 2 Sn(L 2 H)(MeOH)]·MeOH ( 5 ) and [Ph 2 Sn(L 3 H)] ( 6 ), where L 1 H = 2-(( E )-(( Z )-4-hydroxypent-3-en-2-ylidene)amino)-3-(4-hydroxyphenyl)propanoate, L 2 H = ( E )-2-((2-hydroxybenzylidene)amino)-3-(4-hydroxyphenyl)propanoate and L 3 H = ( E )-3-(4-hydroxyphenyl)-2-((1-(2-hydroxyphenyl)ethylidene)amino)propanoate, were synthesized and spectroscopically characterized. The 1 H and 13 C NMR spectra of compounds 1 – 6 displayed two sets of signals for Sn-R 2 (R = Me, n Bu, Ph and Bz) indicating a diastereotopic environment according to the asymmetric nature of the ligand. The 119 Sn NMR data of the compounds in CDCl 3 indicate five-coordinate tin atoms, showing that the bicycloazastannoxide assemblies remain intact as observed in the solid-state structures. The crystal structures of 1 – 6 revealed discrete molecular structures in all cases with distorted trigonal-bipyramidal geometries for 1 – 4 and 6 , and a strongly distorted six-fold coordination for 5 due to association of a MeOH solvent molecule. At the supramolecular level, the molecular structures in 1 – 4 and 6 are linked either through double-bridged O-H⋯O/C-H⋯O synthons ( 1 and 6 ) or single O-H⋯O hydrogen bonds ( 2 – 4 ). The resulting 1D helical strands exhibit varying Sn⋯Sn distances due to the different molecular conformations. The molecules in 5 associate to dimers through two Sn⋯O and O-H⋯O interactions, which are further connected via O-H⋯O hydrogen bonds to give 1D strands containing 22-membered macrocycles. [ABSTRACT FROM AUTHOR]

The reaction of ammonium salts of benzylferrocenyldithiophosphonate ligands [NH 4 ][S 2 P(OR)(Fc)] [R = Bz ( 1 ), 4-( i Pr)-Bz ( 2 ), 4-( t Bu)-Bz ( 3 ), 4-(Ph)-Bz ( 4 ), 3-(OBz)-Bz ( 5 ); Bz = benzyl, Fc = ferrocenyl] with organotin(IV) chlorides Ph 2 SnCl 2 , n Bu 2 SnCl 2 and Ph 3 SnCl, gave the corresponding organotin(IV) benzylferrocenyldithiophosphonates [Ph 2 Sn{S 2 P(OR)(Fc)} 2 ] [R = Bz ( 6 ), 4-( i Pr)-Bz ( 7 ), 4-( t Bu)-Bz ( 8 ), 4-(Ph)-Bz ( 9 ), 3-(OBz)-Bz ( 10 )], [ n Bu 2 Sn{S 2 P(OR)(Fc)} 2 ] [R = Bz ( 11 ), 4-(Ph)-Bz ( 12 )] and [Ph 3 Sn{S 2 P(OBz)(Fc)}] ( 13 ). Compounds 6 – 13 were characterized by elemental analyses, infrared, 1 H, 13 C{ 1 H}, 31 P{ 1 H} and 119 Sn{ 1 H}NMR spectroscopy and ESI mass spectrometry, while complexes 6 , 11 and 13 were also characterized by single-crystal X-ray diffraction studies. The dithiophosphonate ligands display an anisobidentate coordination mode upon interaction with the metal center. The solid-state structures of the disubstituted complexes 6 and 11 exhibit a trans arrangement for the ferrocenyl groups from the dithiophosphonate ligands. [ABSTRACT FROM AUTHOR]

Eight new tin compounds have been obtained from 4-Mercaptophenylacetic acid and trialkytin chloride or dialkytin dichloride. All the compounds were characterized by elemental analysis, FT-IR and NMR ( 1 H, 13 C and 119 Sn) spectroscopy; compounds 1 and 7 were further characterized X-ray crystallography diffraction analyses. The structural analyses reveal that compound 1 has a 1D infinite chain structure; compound 7 has an unusual network structure containing dinuclear 18-membered and tetranuclear 26-membered organotin macrocycles. [ABSTRACT FROM AUTHOR]

The reaction of Au(PPh 3 )Ph with HSnPh 3 yielded the new digold–ditin complex, [Au(PPh 3 )(μ–SnPh 3 )] 2 , 6 in 52% yield. Benzene was also formed. Sn 2 Ph 6 is a major coproduct that was formed by the degradation of 6 . Compound 6 was characterized structurally by a single-crystal X-ray diffraction analysis. The molecule contains two Au(PPh 3 ) groups that are joined by a strong Au–Au bond (2.5590(5) Å in length) that is bridged by two SnPh 3 groups. The metal–metal bonding was analyzed by DFT Mo calculations. The Au–Sn bonding is represented by the HOMO which is a four center: two electron bond. [ABSTRACT FROM AUTHOR]

The reaction of di-iron nonacarbonyl with triphenyl stannane yielded the bow-tie structured Fe 4 (CO) 16 (μ 4 -Sn), 1 . 1 reacted with LPh 3 to afford the corresponding derivatives Fe 4 (CO) 15 (LPh 3 )(μ 4 -Sn), (L = P, 2 , L = Sb, 3 ) by CO substitution on Fe. 2 and 3 were characterized crystallographically by single-crystal X-ray diffraction techniques. [ABSTRACT FROM AUTHOR]

Neutral iron complex, (EBI*)Fe (EBI* = ethylenebis(1-hexamethylindenyl)), and its cationic analogue, [(EBI*)Fe](BF 4 ), have been synthesised. Both rac - and meso- (EBI*)Fe can be isolated but the isomeric distribution of the reaction products was found to be highly sensitive to the reaction conditions employed. The redox behaviour of rac -(EBI*)Fe in solution has been studied by cyclic voltammetry, it shows a one-electron reversible oxidation at −0.7 V vs. (Cp) 2 Fe/(Cp) 2 Fe + . Chemical oxidation of (EBI*)Fe with AgBF 4 gives [(EBI*)Fe](BF 4 ). The molecular structures of rac -(EBI*)Fe and meso -[(EBI*)Fe](BF 4 ) have been determined by single crystal X-ray structure analysis. (EBI*)(SnMe 3 ) 2 was synthesised by the reaction of [(EBI*)]Na 2 with ClSnMe 3 in THF. In solution, only two of the many possible isomers are observed by 1 H NMR spectroscopy. Single crystals of (EBI*)(SnMe 3 ) 2 were grown as pale, plates by the slow cooling to −78 °C of a saturated hexane solution of a mixture of the isomers. 1 H NMR analysis of the crystals showed them to be the isomer with C–SnMe 3 peaks at a chemical shift of – 0.27 ppm. [ABSTRACT FROM AUTHOR]

Two different synthetic routes for the preparation of guanidinate stabilized germanium(II) and tin(II) amide complexes have been established. First, the reaction of one equiv of bulky guanidine ligand either L 1 H or L 2 H [L 1 = {ArNC (N i Pr 2 )NAr} (Ar = 2,6-Me 2 –C 6 H 3 ) and L 2 = {Ar′NC (N i Pr 2 ) NAr′}(Ar′ = 2,6- i Pr 2 -C 6 H 3 )] with two equiv of KN(SiMe 3 ) 2 and one equiv of metal dihalide i.e. , MCl 2 {M = Ge(dioxane) and Sn} led to the formation of guanidinate supported germanium(II) amide , i.e. , L 1 GeN(SiMe 3 ) 2 ( 1 ) and tin amide, i.e. , L 1 SnN(SiMe 3 ) 2 ( 2 ) and L 2 SnN(SiMe 3 ) 2 ( 3 ) complexes, respectively. Second, deprotonation of L 1 H upon treatment with M[N(SiMe 3 ) 2 ] 2 (M = Ge and Sn) in C 6 D 6 at 80 °C for 12 h, afforded the compounds L 1 MN(SiMe 3 ) 2 M = Ge( 1 ) and Sn( 2 ), respectively. X-ray crystal structures of 1 and 2 revealed that both are in monomeric and metal centers in distorted tetrahedral environments with one vertex occupied by a stereo chemically active lone pair of electrons. Furthermore, compounds 1 , 2 and 3 were tested for the catalytic activity in the cyclotrimerization of arylisocyanates, which are exhibiting as excellent catalysts. [ABSTRACT FROM AUTHOR]

Abstract: Catalytic dehydrocoupling of primary and secondary amine boranes and ammonia borane using tin(IV) and tin(II) catalysts is presented. These tin compounds have been demonstrated to dehydrocouple phosphines where catalytic activity was dependent on metal oxidation state. In contrast, the mechanism of amine borane dehydrocoupling appears to be substrate dependent. The most sterically encumbered substrate, tBuNH2BH3, appears to engage in β-hydrogen elimination based on the observation of tBuN = BH2, whereas Me2NHBH3 appears to be involved in a chain-growth process as evidenced by linear diborazane and the absence of amino borane. Though these tin catalysts are moderately active in the spectrum of amine borane dehydrocoupling catalysts, the dependence of mechanism on substrate appears to be unique. [Copyright &y& Elsevier]

• [RR'Sn{(EPPh 2) 2 N}][(EPPh 2) 2 N] derivatives; R = 2-(Me 2 NCH 2)C 6 H 4 ; R' = R, nBu; E = O, S, Se • Dynamic solution behaviour • C,N -coordinated 2-(Me 2 NCH 2)C 6 H 4 groups • κ2-E,E' -chelating organophosphorus ligands • 12-Sn-6 hypercoordinated species The new compounds [{2-(Me 2 NCH 2)C 6 H 4 }(R)Sn{(EPPh 2) 2 N}][(EPPh 2) 2 N] [R = 2-(Me 2 NCH 2)C 6 H 4 , E = O (1), S (2), Se (3) and R = nBu, E = O (4), S (5), Se (6)] were prepared by salt metathesis reactions between [2-(Me 2 NCH 2)C 6 H 4 ](R)SnCl 2 and the potassium salt of the corresponding tetraorganodichalcogenoimidodiphosphinic acid in a 1:2 molar ratio. The multinuclear NMR studies (1H, 13C, 31P, 119Sn, and 77Se where appropriate) showed the equivalence of the 2-(Me 2 NCH 2)C 6 H 4 groups in 1 - 3 and non-equivalent organophosphorus ligands in 1 - 6. The compounds behave as 1:1 electrolytes in solution, with [{2-(Me 2 NCH 2)C 6 H 4 }(R)Sn{(EPPh 2) 2 N}]+ cations and [(EPPh 2) 2 N]− anions. The single-crystal X-ray diffraction studies revealed an ionic structure for 2 and 3. An octahedral coordination environment is realized about tin by two C,N -coordinated 2-(Me 2 NCH 2)C 6 H 4 groups and a κ2-E,E' -chelating organophosphorus [(EPPh 2) 2 N]ˉ anionic ligand. We found a dimeric structure with bridging OHˉ groups and monodentate S- organophosphorus ligands for the hydrolysis product [{2-(Me 2 NCH 2)C 6 H 4 }(nBu)Sn(OH){(SPPh 2) 2 N}] 2 (5h). [Display omitted] [ABSTRACT FROM AUTHOR]

Five new diorganotin(IV) compounds were prepared by reacting diorganotin dichlorides R2SnCl2 (R = Me, nBu and Ph) with sodium salts of the tridentate NO2 ligands (E)-3-hydroxy-2-((2-hydroxybenzylidene)amino)propanoic acid (L1H2Na) and (E)-3-hydroxy-2-((1-(2-hydroxyphenyl)ethylidene)amino)propanoic acid (L2H2Na). The molecular structures of the resulting diorganotin (IV) compounds have been established by elemental analysis and a combination of IR and NMR (1H, 13C, 119Sn) spectroscopy. In all cases, the 119Sn NMR chemical shifts were indicative of five-coordinate tin atoms in solution. However, investigation of compounds [Me2SnL1H]·H2O (1), [Ph2SnL1H]·2C6H6 (3), [Me2SnL2H]·CHCl3 (4) and [Ph2SnL2H] (5) by single-crystal X-ray diffraction revealed that only compound 3 has a distorted trigonal–bipyramidal geometry in the solid state. For compounds 1, 4 and 5 the coordination geometries are distorted octahedral, either due to intermolecular association through Sn⋯O interactions (1) or coordination through the oxygen atom from the pendant CH2OH group (4 and 5). At the supramolecular level, the molecular structures are linked through O–H⋯O hydrogen bonds to give discrete dimeric assemblies (4), 1D chains (3, 5) and 2D hydrogen bonded layers (1). [ABSTRACT FROM AUTHOR]

Abstract: Thirteen organotin(IV) and low valent complexes of group 14 (Ge, Sn, Pb) containing L NO ligand(s) (where L NO is 2-(N,N-dimethylaminomethyl)phenolate) were synthesized and its structure described by NMR techniques in solution and X-ray techniques in the solid state (for L2 NO SnPh2, L2 NO SnCl2, L2 NO Ge and L NO SnCl which forms a dimer). Structures and properties of prepared species have been compared with previously published germanium and tin compounds containing –OCH2CH2NMe2 as O,N- or L CN (where L CN is 2-(N,N-dimethylaminomethyl)phenyl) as C,N-chelating ligands. The solid state structures containing L NO ligand(s) reveal much stronger intramolecular N → Sn coordination than complexes containing latter two ligands. [Copyright &y& Elsevier]

Abstract: The compounds Ru4(CO)12(GePh3)2(μ-H)4, 1 and Ru4(CO)12(SnPh3)2(μ-H)4, 2 were obtained from the reactions of Ru4(CO)13(μ-H)2 with HGePh3 and HSnPh3, respectively. Both compounds contain a nearly planar butterfly structure for the four metal atoms with two GePh3/SnPh3 ligands and four bridging hydride ligands around the periphery of the cluster. When heated, 1 and 2 were converted into the complexes Ru4(CO)12(μ4-EPh)2, 3, E = Ge, and 4, E = Sn, by cleavage of two phenyl groups from each of the GePh3 ligands. Compounds 3 and 4 contain square planar arrangements of the four ruthenium atoms with quadruply bridging germylyne and stannylyne ligands on opposite sides of the square plane. The bonding and electronic transitions of 3 were analyzed by DFT computational analyses. [Copyright &y& Elsevier]

Abstract: The metathesis of CpMn(CO)(NO)SnCl3 (I) and anionic carbonyls (ML−) provided trinuclear mixed-metal complexes of general formula CpMn(CO)(NO)SnCl2ML (VIII–XII; Cp = C5H5, Cp′ = C5H4CH3, Cp″ = C5H3(C4H9)2). Along with XII, the product of transmetallation Cp″Mo(CO)3SnCl3 (XIII) was separated. Interaction of I with gave the mixed-metal cluster Cp(CO)(NO)Mn–SnCl2–Fe(CO)4–SnCl2–MnCp(CO)(NO) (XIV) which contain the pentanuclear metal-chain. As determined by the single crystal XRD analysis, the Mn–Sn distance in CpMn(CO)(NO)Sn fragment is 0.2 Å shorter than the expected value based on the Mn/Sn sum of covalent radii (SCR). From the other hand, the shortening of Sn–ML distances is in an accord with the donor ability of an ML fragment in the row Co(CO)4 ∼ Mn(CO)5 < Fe(CO)4 < CpMn(CO)(NO < Cp′Mo(CO)3 < Cp′W(CO)3 < Cp″Mo(CO)3 owing to the additive back donation of the transition metal d-LEP to Sn vacant orbitals. The absence of substantial elongation of the Sn–Cl distances may result from the π-back donation of transition metal d-orbitals to tin d-orbitals. [Copyright &y& Elsevier]

Abstract: Tetraphenylporphyrinatotin(IV) trifluoromethanesulfonate, [SnIV(TPP)(OTf)2], and tetraphenylporphyrinatotin(IV) tetrafluoroborate, [SnIV(TPP)(BF4)2], were used as efficient catalysts for olefination of aldehydes with EDA in the presence of PPh3. These high-valent tin porphyrins catalyzed olefination of aldehydes in high yields and short reaction times at room temperature. The reaction rate depended on the nature of substituents on aldehyde; electron poor aldehydes reacted faster than electron rich aldehydes. The olefination of aldehydes indicated that the reactions are very selective and all products are trans-isomer. Both catalysts were reused four consecutive times without loss of their catalytic activity. [Copyright &y& Elsevier]

Abstract: Two structurally related organometallic compounds containing both Fe and Sn have been examined by temperature-dependent Mössbauer effect (ME) spectroscopy to elucidate the bonding and lattice dynamics of the metal atoms. The iron atom parameters are not otherwise remarkable and the motion is essentially isotropic in the temperature range 90 < T < 250 K and in good agreement with the corresponding X-ray data. In the case of the Sn resonances, there is a marked difference in the QS parameter of the two differing tin atoms, and in addition there is a significant difference in the vibrational data extracted from the ME studies and the X-ray derived values. The vibrational amplitudes of all metal atoms are compared and discussed. [Copyright &y& Elsevier]

Abstract: The new distannadiyl-ansa half sandwich complex [{κ 1-SntBu2SntBu2-(η 5-C5H5)}Fe(CO)2] was synthesized via a non-bridged half sandwich precursor upon treatment with LDA. The compound exhibits a high ring strain within the bridge, which enables further reactivity as exemplarily demonstrated for the insertion of chalcogens. Finally, treatment of the ansa complex with [Pd(CNtBu)2] results in the oxidative addition of the distannadiyl bridge to the palladium centre. [Copyright &y& Elsevier]

Abstract: Stannylated polymers based on the polyfluorene backbone have been synthesized and used in the Stille reaction as recyclable reagents, minimizing the generation of toxic tin residues. [Copyright &y& Elsevier]

Abstract: The reaction of 2,6-dimethoxypyridine-3-carboxylic acid (DMPH) with different precursors [Ti(η5-C5H5)2Cl2], [Ti(η5-C5H4Me)2Cl2], [Ti(η5-C5H4SiMe3)(η5-C5H5)Cl2], [Ti(η5-C5Me5)Cl3], SnMe3Cl and Ga t Bu3 yielded the complexes [Ti(η5-C5H5)2(DMP-κO)2] (1), [Ti(η5-C5H4Me)2(DMP-κO)2] (2), [Ti(η5-C5H4SiMe3)(η5-C5H5)(DMP-κO)2] (3), [Ti(η5-C5Me5)(DMP-κ2 O,O′)3] (4), [SnMe3(μ-DMP-κO:κO′)]∞ (5), and [Ga t Bu2(μ-DMP-κO:κO′)]2 (6). 1–6 have been characterized by spectroscopic methods and the molecular structure of the complexes 1, 2, 3, 5 and 6 have been determined by X-ray diffraction studies. The cytotoxic activity of 1–6 was tested against the tumour cell lines human adenocarcinoma HeLa, human myelogenous leukaemia K562, human malignant melanoma Fem-x and human breast carcinoma MDA-MB-361. The results of this study show a higher cytotoxicity of the tin(IV) and gallium(III) derivatives in comparison to their titanium(IV) counterparts. Furthermore, the different titanium compounds showed differences in their cytotoxicities with a higher activity of complex 4 (mono-(cyclopentadienyl) derivative) compared to that of 1–3 (bis-(cyclopentadienyl) complexes). A qualitative UV–vis study of the interactions of these complexes with DNA has also been carried out. [Copyright &y& Elsevier]

Abstract: A reinvestigation of the reaction of Ir(CO)Cl(PPh3)2, 1 with HSnPh3 has revealed that the oxidative-addition product Ir(CO)Cl(PPh3)2(H)(SnPh3), 2 has the H and SnPh3 ligands in cis-related coordination sites. Compound 2 reacts with a second equivalent of HSnPh3 by a Cl for H ligand exchange to yield the new compound H2Ir(CO)(SnPh3)(PPh3)2, 3. Compound 3 contains two cis- related hydride ligands. Under an atmosphere of CO, 1 reacts with HSnPh3 to replace the Cl ligand with SnPh3 and one of the PPh3 ligands with a CO ligand and also adds a second equivalent of CO to yield the 5-coordinate complex Ir(CO)3(SnPh3)(PPh3), 4. Compound 4 reacts with HSnPh3 by loss of CO and oxidative addition of the Sn-H bond to yield the 6-coordinate complex HIr(CO)2(SnPh3)2(PPh3), 5 that contains two trans-positioned SnPh3 ligands. [Copyright &y& Elsevier]

Abstract: The first examples of bridging tin- and germanium-substituted metallocarboxylate ligands have been obtained from the reactions of Ph3SnOH and Ph3GeOH with Os3(CO)12 under basic conditions. Two products: Os3(CO)10(μ-η2-O=COSnPh3)(μ-OMe), 1 (18% yield) and Os3(CO)10(μ-OMe)(μ-OH), 2 (6.9% yield) were obtained from the reaction of Ph3SnOH with Os3(CO)12 in the presence of [Bu4N]OH in methanol solvent. The compound Os3(CO)10(μ-η2-O=COGePh3)(μ-OMe), 3 (7.3% yield) was prepared similarly by using Ph3GeOH in place of Ph3SnOH. Each of the products 1–3 were characterized structurally by single-crystal X-ray diffraction analysis. Compounds 1 and 3 each contain an μ-η2-O=COMPh3, M = Sn or Ge ligand bridging a pair of osmium atoms in a triosmium carbonyl cluster complex. [Copyright &y& Elsevier]

Abstract: Reaction of three hexadentate ligands (L1–L3) derived from 1,4-benzoquinone bis(aminoalcohols) with diorganotin oxides (R2Sn-O)n (with R = Me, nBu, Ph) in 1:2 stoichiometric proportions lead to the formation of dinuclear tin compounds of the composition [(R2Sn)2(L)], wherein the five-coordinate metal centers are embedded in distorted trigonal-bipyramidal polyhedra. X-ray diffraction analysis revealed that diorganotin complexes carrying n-butyl groups tend to associate further through intermolecular O⋯Sn interactions to give 1D polymeric chains, while diphenyltin analogues tend to be monomeric. On the other hand, using 2,5-dihydroxy-3,6-dichloro-1,4-benzoquinone as ligand (L4) in 1:1 reactions with the diorganotin oxide derivatives, 1D polymeric complexes of the composition [R2Sn(L4)(DMSO)]n with seven-coordinate metal centers in distorted pentagonal-bipyramidal coordination polyhedra were obtained. In this case, the presence of different substituents attached to the tin atoms (Me, nBu, Ph) had no influence on the molecular composition of the products, but on the conformation of the polymeric chain, which was either planar (R = Me), slightly distorted from planarity (R = nBu) or ondulated (R = Ph). [Copyright &y& Elsevier]

Abstract: Two series of di and trinuclear chlorodiorganotin(IV) complexes derived from bis- and tris-dithiocarbamate ligands have been prepared and structurally characterized. The dinuclear complexes 1–2 of the composition {(R2SnCl)2(bis-dtc)} (1, R = Me; 2, R =  n Bu) have been obtained from R2SnCl2 (R = Me, n Bu) and the triethylammonium salt of N,N′-dibenzyl-1,2-ethylene-bis(dithiocarbamate). The trinuclear complexes 3–9 with the general formula {(R2SnCl)3(tris-dtc)} 3, R = Me, tris-dtc = tris-dtc-Me; 4, R = Me, tris-dtc = tris-dtc- i Pr; 5, R = Me, tris-dtc = tris-dtc-Bn; 6, R = n Bu, tris-dtc = tris-dtc-Me; 7, R =  n Bu, tris-dtc = tris-dtc- i Pr; 8, R = n Bu, tris-dtc = tris-dtc-Bn; 9, R = t Bu, tris-dtc = tris-dtc-Me) were prepared from R2SnCl2 (R = Me, n Bu, t Bu) and the potassium dithiocarbamate salts of (tris[2-(methylamino)ethyl]amine) (tris-dtc-Me), (tris[2-(isopropylamino)ethyl]amine) (=tris-dtc- i Pr) and (tris[2-(benzylamino)ethyl]amine) (=tris-dtc-Bn). Compounds 1–9 have been analyzed as far as possible by elemental analysis, FAB+ mass spectrometry, IR and NMR (1H, 13C, 119Sn) spectroscopy, and single-crystal X-ray diffraction analysis. The solid state and solution studies showed that the dtc ligands are coordinated to the tin atoms in the anisobidentate manner. In all cases the metal centers are five-coordinate. The coordination geometry is intermediate between square-pyramidal and trigonal-bipyramidal coordination polyhedra with τ-values in the range of 0.32–0.53. For the members of each series characterized in the solid state by X-ray diffraction analysis, different molecular conformations were found. The crystal structures show the presence of C–H⋯Cl, C–H⋯S, C–H⋯π, S⋯Cl, S⋯S, Cl⋯Sn and S⋯Sn contacts. [Copyright &y& Elsevier]

Abstract: Here we report the synthesis and crystal structure of a new [2]ferrocenophane [Fe(η5-C5H4)2(SntBu2)2] with a sterically demanding distannanediyl bridge. The reactivity of the title compound towards selected main group elements was examined and in addition, this reactivity pattern was established for the related diboranediyl bridged [2]ferrocenophane [Fe(η5-C5H4)2(BNMe2)2]. [ABSTRACT FROM AUTHOR]

Abstract: The triphenyltin(IV) carboxylate compounds [{SnPh3(O2CCH2SXyl)} ∞ ] (1) (Xyl = 3,5-Me2C6H3) and [{SnPh3(O2CCH2SMes)} ∞ ] (2) (Mes = 2,4,6-Me3C6H2) have been synthesized by the reaction of SnPh3Cl with one equivalent of xylylthioacetic acid or mesitylthioacetic acid, respectively. 1 and 2 have been characterized by spectroscopic methods. The cytotoxic activity of 1 and 2 was tested against human tumour cell lines from four different histogenic origin: 8505C (anaplastic thyroid cancer), DLD-1 (colon cancer) and the cisplatin sensitive A253 (head and neck cancer) and A549 (lung carcinoma) and compared with those of the reference complex cisplatin. Interestingly, the cytotoxic activities of the carboxylate derivatives were higher than those of cisplatin against all the studied cells. DNA-interaction tests have been also carried out. Solutions of all the studied complexes have been treated with different concentrations of fish sperm DNA (FS-DNA), observing modifications of the UV spectra with intrinsic binding constants of 1.68 × 105 and 1.02 × 105, M−1 for 1 and 2, respectively. In addition, the molecular structure of 2 has been determined by single crystal X-ray diffraction studies, observing that 2 consists of a 1-D coordination polymer in which the tin atoms present a five-coordinated geometry by coordination of two different oxygen atoms of two crystallographically dependent carboxylato ligands. [Copyright &y& Elsevier]

Abstract: The treatment of tin(II) trifluoromethanesulfonate with three differently-sized crown ethers [12]crown-4, [15]crown-5 and [18]crown-6 results in the formation of tin complexes that exhibit dramatically different structural features. The compounds are investigated using experimental techniques and density functional theory calculations. [Copyright &y& Elsevier]

Abstract: Metalloid cluster compounds are ideal model compounds for the area between the molecular and solid state, i.e. the nanometer regime. For the synthesis of metalloid cluster compounds, the disproportionation reaction of a metastable subhalide is a fruitful synthetic route. In the case of tin, monohalides are needed for this synthetic route as tin(II) halides are too stable to be used. Due to thermodynamic data, gaseous SnBr should be formed at 1370°C, and by applying a co-condensation technique it can be trapped at −196°C and prepared in synthetic scale. Herein first analyses of SnBr are presented, showing that SnBr is more reactive than the corresponding GeBr, already disproportionating quantitatively to elemental tin and SnBr2 on heating to room temperature. By applying nitrogen-based donor molecules like NnBu3 or pyridine, the reactivity can be moderated and the solubility is enhanced leading e.g. to an SnBr emulsion, which can be used for the synthesis of metalloid cluster compounds of tin. [Copyright &y& Elsevier]

Abstract: An insoluble polymer-supported phenyltin reagent was successfully used in Stille cross-coupling reactions with aryl- and heteroaryl-halides. Cross-coupling products were isolated in good to high yields with very low contamination by tin and palladium residues after removal of the residual supported organotin halide. The regeneration and recyclability of the supported phenyltin reagent were also examined and proved to be possible, but required palladium cleaning of the grafted polymer to be efficient along 4 cycles when Pd(PPh3)4 was used as catalyst. [Copyright &y& Elsevier]

Abstract: The bimetallic cluster complex Fe2(μ-)2(CO)8, 1, selectively activates the benzylic C–H bond in solvent toluene at reflux conditions to afford the complex Fe2[μ-SnBut(CH2Ph)]2(CO)8, 3, where two of the But groups in 1 have been replaced with benzyl groups. Similarly 1 also activates the benzylic C–H bond in solvent m-xylene to yield complexes Fe2[μ-SnBut(m-CH2PhMe)]2(CO)8, 4, Fe2[μ-SnBut(m-CH2PhMe)][μ-Sn(m-CH2PhMe)2](CO)8, 5, and Fe2[μ-Sn(m-CH2PhMe)2]2(CO)8, 6, where two, three and four of the But groups in 1 have been replaced by m-tolyl groups, respectively. A mechanism based on a radical pathway is proposed for the C–H activation by 1. [Copyright &y& Elsevier]