Synthesis, Spectroscopic Properties and Crystal Structures of Dibenzyltin（IV） Dithiobenzoate and Chlorodibenzyltin（IV） Thiobenzoate

Two dibenzyltin(IV) complexes with thiobenzoate ligand, (PhCH2)2Sn(SOCPh)2 (1) and (PhCH2)2Sn(C1)SOCPh (2), have been synthesized by the reaction of dibenzyltin(IV) dichloride with thiobenzoic acid in the presence of organic base Et3N and characterized by IR, ^1H NMR spectroscopy and elemental analysis. Their crystal structures were determined by X-ray single crystal diffraction analysis. In the crystals of 1, the tin atom is six-coordinated in a distorted octahedron configuration. In the crystals of 2, the molecular packing in unit cell reveals that the two adjacent molecules are symmetrically linked to each other to form a dimer with intermolecular Sn…C1 distances of 0.3591 (2) nm and the tin atom is five-coordinated in a distorted trigonal bipyramid configuration.     

Synthesis,properties and crystal structural characterization of diorganotin(IV) derivatives of 2‐mercapto‐6‐nitrobenzothiazole

The diorganotin(IV) dichlorides R₂SnCl₂ (R: Ph, PhCH₂ or n‐Bu) react with 2‐mercapto‐6‐nitrobenzothiazole (MNBT) in benzene to give [Ph₂SnCl(MNBT)] ( 1 ), [(PhCH₂)₂Sn(MNBT)₂] ( 2 ) and [(n‐Bu)₂Sn(MNBT)₂] ( 3 ). The three complexes have been characterized by elemental analysis and IR, ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopies. X‐ray studies of the crystal structures of 1 , 2 and 3 show the following. The tin environment for complex 1 is distorted cis‐trigonal bipyramid with chlorine and nitrogen atoms in apical positions. The structure of complex 2 is a distorted octahedron with two benzyl groups in the axial sites. The geometry at the tin atom of complex 3 is that of an irregular octahedron. Interestingly, intra‐molecular non‐bonded Cl…S interactions and S…S interaction were recognized in the crystallographic structures of 1 and 3 respectively. As a result, complex 1 is a polymer and complex 3 is a dimer. Copyright © 2003 John Wiley & Sons, Ltd.     

Synthesis and characterization of organotin complexes with dithiocarbamates and crystal structures of (4‐NCC6H4CH2)2Sn(S2CNEt2)2 and (2‐ClC6H4CH2)2 Sn(Cl)S2CNBz2

Ten organotin derivatives with dithiocarbamates of the formulae (4‐NCC₆H₄CH₂)₂Sn(S₂CNEt₂)₂ (1), (4‐NCC₆H₄CH₂)₂Sn(S₂CNBz₂)₂ (2), (4‐NCC₆H₄CH₂)₂Sn[S₂CN(CH₂CH₂)₂NCH₃]₂ (3), (2‐ClC₆H₄CH₂)₂ Sn(S₂CNEt₂)₂ (4), (2‐ClC₆H₄CH₂)₂Sn(S₂CNBz₂)₂ (5), (4‐NCC₆H₄CH₂)₂Sn(Cl)S₂CNEt₂ (6), (4‐NCC₆H₄CH₂)₂Sn(Cl)S₂CNBz₂ (7), (4‐NCC₆H₄CH₂)₂Sn(Cl)S₂CN(CH₂CH₂)₂NCH₃ (8), (2‐ClC₆H₄CH₂)₂ Sn(Cl)S₂CNEt₂ (9) and (2‐ClC₆H₄CH₂)₂Sn(Cl)S₂CNBz₂ (10) have been prepared. All complexes were characterized by elemental analyses, IR and NMR. The crystal structures of complexes 1 and 10 were determined by X‐ray single crystal diffraction. For complex 1, the central tin atom exists in a skew‐trapezoidal planar geometry defined by two asymmetrically coordinated dithiocarbamate ligands and two 4‐cyanobenzyl groups. In addition, because of the presence of close intermolecular non‐bonded contacts, complex 1 is a weakly‐bridged dimer. In complex 10, the central tin atom is rendered pentacoordinated in a distorted trigonal bipyramidal configuration by coordinating with S atoms derived from the dithiocarbamate ligand. In vitro assays for cytotoxicity against five human tumor cell lines (MCF‐7, EVSA‐T, WiDr, IGROV and M226) furnished the significant toxicities of the title complexes. Copyright © 2006 John Wiley & Sons, Ltd.     

Syntheses and Crystal Structure of Six－coordinated Diorgnotin Complexes with 2,5－Dimercapto－4－phenyl－1,3,4－thiodiazole

The reactions of diorganotin dichloride [Ph_2SnCl_2, (PhCH_2)_2-SnCl_2 or (n-Bu)_2SnCl_2] with potassium salt of 2,5-dimercapto-4-phenyl-1, 3, 4-thiodiazole gave complexes R_2Sn (S_3N_2C_8H_5)_2(4: R=Ph; 5: R=PhCH_2 and 6: R=n-Bu), respectively.Characterizations were carried out for all complexes by IR, ~1HNMR spectra and X-ray crystallography analysis. Including theSn…N interaction, the three complexes all have six-coordinateddistorted octahedral geometry. Based on the requence of stereo-chemical constraint sequence, phenyl≈benzyl>n-butyl, the lessthe effect of the stereochemical constraint of R groups, the     

Synthesis and spectral studies of diorganotin heterocyclic dithiocarbamate complexes and crystal structures of (2‐F‐Bz)2Sn(Cl) S2CN(CH2CH2)2NEt and (3‐Cl‐Bz)2Sn [S2CN(CH2CH2)2NEt]2 ⋅ 0.5HN(CH2CH2)2NH

Some new diorganotin(IV) complexes of heterocyclic dithiocarbamate having general formula R₂Sn(Cl)S₂CNR'₂ and R₂Sn(S₂CNR'₂)₂ [R = 2‐F‐Bz, 3‐Cl‐Bz; NR'₂ = N(CH₂CH₂)₂NMe, N(CH₂CH₂)₂NEt, and N(CH₂CH₂)₂NBz] have been prepared, respectively. Elemental analyses, IR, and NMR spectral data characterized all compounds. The crystal structures of (2‐F‐Bz)₂Sn(Cl)S₂CN(CH₂CH₂)₂NEt 2 and (3‐Cl‐Bz)₂Sn[S₂CN(CH₂CH₂)₂NEt]₂ ⋅ 0.5 HN(CH₂CH₂)₂NH 5 were determined by single crystal X‐ray diffractometer. In the crystal of complex 2 , the tin atom is rendered five‐coordination in a trigonal bipyramidal configuration by coordinating with S atoms of dithiocarbamate groups. For complex 5 , the central Sn atom exists in a skew‐trapezoidal planar geometry defined by two asymmetrically coordinated dithiocarbamate ligands and two 3‐chlorobenzyl groups. © 2005 Wiley Periodicals, Inc. 16:271–277, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20096     

Die ersten Röntgenstrukturen kationischer Diorganylzinn(IV)‐Dichelate [R2Sn(L–L)2]2⊕ mit zweizähnigen Phosphanoxid‐Liganden: Di(methansulfonyl)amid als nichtkoordinierendes Gegenion

Polysulfonylamines. CXI. The First X‐Ray Structures of Cationic Diorganyltin(IV) Dichelates [R₂Sn(L–L)₂]^2⊕ Involving Bidentate Phosphine Oxide Ligands: Di(methanesulfonyl)amide as a Non‐Coordinating Counter‐Ion The reaction of Me₂Sn(A)₂, where A^⊖ = (MeSO₂)₂N^⊖, with DPPOE = ethane‐1,2‐diylbis(diphenylphosphine oxide) or CDPPOET = cis‐ethene‐1,2‐diylbis(diphenylphosphine oxide) yields the ionic dichelates [Me₂Sn(dppoe)₂]^2⊕ · 2 A^⊖ ( 1 ; monoclinic, space group P2₁/c) and [Me₂Sn(cdppoet)₂]^2⊕ · 2 A^⊖ ( 2 ; monoclinic, P2₁/n). A solvated variety of 2 , [Me₂Sn(cdppoet)₂]^2⊕ · 2 A^⊖ · Et₂O · 0.15 MeCN ( 4 ; triclinic, P 1), was serendipitously obtained by thermal degradation of the new compound [Me₂Sn(A)(μ‐OH)]₂ · 2 CDPPOET in an MeCN/Et₂O medium. The crystals of 1 , 2 and 4 consist of discrete formula units (one independent unit for 1 and 2 , two independent units for 4 ); in the structure of 4 , the solvent molecules are located in lattice cavities. All the tin atoms lie on crystallographic inversion centres and display moderately distorted octahedral C₂O₄ coordinations with short Sn–O bonds in the range 218–223 pm. Within the formula units, the anions are connected to the P–CH donor groups of the chelating ligands by C–H…O/N interactions, some of which are remarkably short (e.g. in 1 : H…O 220 pm, C–H…O 170°; H…N 242 pm, C–H…N 153°).     

Structural insights into methyl‐ or methoxy‐substituted 1‐(α‐aminobenzyl)‐2‐naphthol structures: the role of C—H…π interactions

Aminobenzylnaphthols are a class of compounds containing a large aromatic molecular surface which makes them suitable candidates to study the role of C—H…π interactions. We have investigated the effect of methyl or methoxy substituents on the assembling of aromatic units by preparing and determining the crystal structures of (S,S)‐1‐{(4‐methylphenyl)[(1‐phenylethyl)amino]methyl}naphthalen‐2‐ol, C₂₆H₂₅NO, and (S,S)‐1‐{(4‐methoxyphenyl)[(1‐phenylethyl)amino]methyl}naphthalen‐2‐ol, C₂₆H₂₅NO₂. The methyl group influenced the overall crystal packing even if the H atoms of the methyl group did not participate directly either in hydrogen bonding or C—H…π interactions. The introduction of the methoxy moiety caused the formation of new hydrogen bonds, in which the O atom of the methoxy group was directly involved. Moreover, the methoxy group promoted the formation of an interesting C—H…π interaction which altered the orientation of an aromatic unit.     

Synthesis and characterization of diorganotin(IV) derivatives from rhodanine (HRd): crystal structures of [(PhCH2)2Sn(Rd)(μ-OH)]2 and [n-Bu2Sn(Rd)(μ-OH)]2

The diorganotin(IV) complexes, [R₂Sn(Rd)(μ-OH)]₂ (R?=?Me (1), PhCH₂ (2), n-Bu (3), Ph (4); HRd?=?rhodanine), have been synthesized and characterized by IR and multinuclear (¹H, ¹³C, ¹¹⁹Sn) NMR spectroscopy. The structures of complexes 2 and 3 have been determined by single-crystal X-ray diffraction. Both crystal structures of 2 and 3 show the presence of asymmetrically bridging hydroxy groups leading to an Sn₂O₂ unit. Each atom in complex 1 is also coordinated by an N atom of ligand and two C atoms of the alkyl groups, so the Sn environment is based on a trigonal bipyramid. While in complex 2, a weak intermolecular Sn–O interaction has also been found between the two adjacent molecules, so the geometry of the Sn atom can be best described as six-coordinate octahedral. The salient feature of the supramolecular structure of complex 3 is that of a 1D polymer, in which the discrete molecules are connected through weak intermolecular Sn?···?O interactions.     

Synthese und Kristallstruktur von [(PhCH2)2GaF(tBuNH2)]2 · 2 THF

Synthesis and Crystal Structure of [(PhCH₂)₂GaF(^tBuNH₂)]₂ · 2 THF (PhCH₂)₂GaF reacts with ^tBuNH₂ to the adduct [(PhCH₂)₂GaF(^tBuNH₂)] ( 1 ). 1 was characterized by NMR, IR and MS techniques. 1 can be recrystallized from THF forming crystals of [ 1 ]₂ · 2 THF. According to an X-ray structure analysis [ 1 ]₂ · 2 THF consists of dimers of 1 formed by hydrogen bridges. The THF molecules are coordinated to [ 1 ]₂ by hydrogen bridges, too.     

Organtin complexes of 2,5‐dithiobiurea (H2dtbu): The crystal structures of (Ph3Sn)2(dtbu) and [(n‐Bu)2SnCl]2(dtbu)

A series of organotin(IV) complexes of two types, [R₃Sn]₂(dtbu) (R = PhCH₂ 1 , Ph 2 , n‐Bu 3 , H₂dtbu = 2,5‐dithiobiurea), [R₂SnCl]₂(dtbu) (R = PhCH₂ 4 , Ph 5 , n‐Bu 6 ) have been synthesized and characterized by elemental analysis, IR, and NMR (¹H, ¹¹⁹Sn) spectroscopy. The structures of 2 and 6 have been determined by X‐ray crystallography. Crystal structures show that both complexes 2 and 6 are the symmetric dinuclear unit. Interestingly, supramolecular structures show that complex 2 has formed a linear chain through N H⋅⋅⋅S hydrogen bonding and 6 has formed a two‐dimensional network in perfect bc plane connected through N H⋅⋅⋅Cl hydrogen bonding and nonbonded S⋅⋅⋅S interactions. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:435–442, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20456     

Three isostructural solvates of a tetrahydrofurochromenone derivative

Isostructurality is more likely to occur in multicomponent systems. In this context, three closely related solvates were crystallized, namely, benzene (C₂₇H₂₁BrO₆·C₆H₆), toluene (C₂₇H₂₁BrO₆·C₇H₈) and xylene (C₂₇H₂₁BrO₆·C₈H₁₀) with methyl 3a‐acetyl‐3‐(4‐bromophenyl)‐4‐oxo‐1‐phenyl‐3,3a,4,9b‐tetrahydro‐1H‐furo[3,4‐c ]chromene‐1‐carboxylate, and their crystal structures determined. All three structures belong to the same space group (P ) and display similar unit‐cell dimensions and conformations, as well as isostructural crystal packings. The isostructurality is confirmed by unit‐cell and isostructural similarity indices. In each solvate, weak C—H…O and C—H…π interactions extend the molecules into two‐dimensional networks, which are further linked by C—H…Br and Br…Br interactions into three‐dimensional networks. The conformation of the core molecule is predominantly responsible for governing the isostructurality.     

Z/E‐Isomerism of 3‐[4‐(dimethylamino)phenyl]‐2‐(2,4,6‐tribromophenyl)acrylonitrile: crystal structures and secondary intermolecular interactions

The Z and E isomers of 3‐[4‐(dimethylamino)phenyl]‐2‐(2,4,6‐tribromophenyl)acrylonitrile, C₁₇H₁₃Br₃N₂, ( 1 ), were obtained simultaneously by a Knoevenagel condensation between 4‐(dimethylamino)benzaldehyde and 2‐(2,4,6‐tribromophenyl)acetonitrile, and were investigated by X‐ray diffraction and density functional theory (DFT) quantum‐chemical calculations. The (Z)‐( 1 ) isomer is monoclinic (space group P2₁/n, Z′ = 1), whereas the (E)‐( 1 ) isomer is triclinic (space group P, Z′ = 2). The two crystallographically‐independent molecules of (E)‐( 1 ) adopt similar geometries. The corresponding bond lengths and angles in the two isomers of ( 1 ) are very similar. The difference in the calculated total energies of isolated molecules of (Z)‐( 1 ) and (E)‐( 1 ) with DFT‐optimized geometries is ∼4.47 kJ mol⁻¹, with the minimum value corresponding to the Z isomer. The crystal structure of (Z)‐( 1 ) reveals strong intermolecular nonvalent Br…N [3.100 (2) and 3.216 (3) Å] interactions which link the molecules into layers parallel to (10). In contrast, molecules of (E)‐( 1 ) in the crystal are bound to each other by strong nonvalent Br…Br [3.5556 (10) Å] and weak Br…N [3.433 (4) Å] interactions, forming chains propagating along [110]. The crystal packing of (Z)‐( 1 ) is denser than that of (E)‐( 1 ), implying that the crystal structure realized for (Z)‐( 1 ) is more stable than that for (E)‐( 1 ).     

Reaction of dimethylplatinum(II) complexes with PhCH2CH2Br: Comparative reactivity with CH3CH2Br and PhCH2Br and synthesis of Pt(IV) complexes

Oxidative addition of 2‐phenylethylbromide (PhCH₂CH₂Br) to dimethylplatinum(II) complexes [PtMe₂(NN)] ( 1a , NN = 2,2′‐bipyridine (bpy); 1b , NN = 1,10‐phenanthroline (phen)) afforded the new organoplatinum(IV) complexes [PtMe₂(Br)(PhCH₂CH₂)(bpy)], as a mixture of trans ( 2a ) and cis ( 3a ) isomers, and [PtMe₂(Br)(PhCH₂CH₂)(phen)], as a mixture of trans ( 2b ) and cis ( 3b ) isomers, respectively. The new Pt(IV) complexes were readily characterized using multinuclear (¹H and ¹³C) NMR spectroscopy and elemental microanalysis. The crystal structure of 2a was further determined using X‐ray crystallography indicating an octahedral geometry around the platinum centre. A comparison of reactivity of RCH₂Br reagents (R = CH₃, Ph or PhCH₂) in their oxidative addition reactions with complex 1a , with an emphasis on the effects of the R groups of alkyl halides, was also conducted using density functional theory.     

Synthesis and characterization of tribenzyltin(IV) and dibenzyltin(IV) complexes of 2-{[(2Z)-3-hydroxy-1-methyl- 2-butenylidene]amino}acetic acid: Crystal structure of tribenzyl{2-{[(2Z)-3-hydroxy-1-methyl-2-butenylidene] amino}acetato}tin(IV)

Reactions of equimolar quantities of potassium 2-{[(2Z)-3-hydroxy-1-methyl-2-butenylidene]amino}acetate, with R _n SnX_4?n (R: benzyl– and n=2 or 3) in methanol yielded products of compositions LHSn(PhCH₂)₃ and LSn(PhCH₂)₂, respectively. The complexes were characterized by microanalysis, IR, NMR (¹H, ¹³C, ¹¹⁹Sn) and ^119mSn Mössbauer spectroscopy. A full characterization of the structure of the complex, tribenzyl{2-{[(2Z)-3-hydroxy-1-methyl-2-butenylidene]amino}acetato}tin(IV), was carried out by single crystal X-ray crystallography. The compound exists as centrosymmetric dimers in which two ligand molecules bridge the two tin centres. Each of the tin atoms in the dimeric unit is five coordinate in an approximately trigonal bipyramidal configuration, with carbon atoms in the equatorial positions and oxygen atoms arranged axially.     

Synthesis and crystal structures of a 3‐acetylated (20S,24S)‐ocotillol‐type saponin and its C‐24 epimer

In order to study the in vivo protective effect on myocardial ischemia, (20S ,24R )‐epoxydammarane‐12β,25‐diol, (V), and (20S ,24S )‐epoxydammarane‐12β,25‐diol, (VI), were synthesized through a novel synthetic route. Two key intermediates, namely (20S ,24R )‐3‐acetyl‐20,24‐epoxydammarane‐3β,12β,25‐triol, (III) [obtained as the hemihydrate, C₃₂H₅₄O₅·0.5H₂O, (IIIa ), and the ethanol hemisolvate, C₃₂H₅₄O₅·0.5C₂H₅OH, (IIIb ), with identical conformations but different crystal packings], and (20S ,24S )‐3‐acetyl‐20,24‐epoxydammarane‐3β,12β,25‐triol, C₃₂H₅₄O₅, (IV), were obtained during the synthesis. The structures were confirmed by ¹H NMR, ¹³C NMR and HRMS analyses, and single‐crystal X‐ray diffraction. Molecules of (IIIa ) are extended into a two‐dimensional network constructed with water molecules linked alternately through intermolecular O—H…O hydrogen bonds, which are further stacked into a three‐dimensional network. Compound (IIIb ) contains two completely asymmetric molecules, which are linked in a disordered manner through intermolecular C—H…O hydrogen bonds. While the crystal stacks in compound (IV) are linked via weak C—H…O hydrogen bonds, the hydrogen‐bonded chains extend helically along the crystallographic b axis.     

Kaliumtriamidostannat(II), K[Sn(NH2)3] – Synthese und Kristallstruktur

Potassium Triamidostannate(II), K[Sn(NH₂)₃] – Synthesis and Crystal Structure Rusty‐red crystals of K[Sn(NH₂)₃] were obtained by the reaction of SnBr₂ and KNH₂ in a 1 : 3 molar ratio in liquid ammonia at 233 K in the form of platelets. The structure was determined from single crystal X‐ray diffractometer data: Space group P3; Z = 2; a = 6.560(1) Å, c = 7.413(2) Å. The structure contains trigonal pyramidal complex anions [Sn(NH₂)₃]^– and potassium cations. These ions are arranged to one another following the motif of a strongly distorted hexagonal close packing of sequence A(Sn) B(Sn) A′(K) B′(K) …     

A pair of diastereomeric 1:2 salts of (R)‐ and (S)‐2‐methylpiperazine with (2S,3S)‐tartaric acid

The crystal structures of a pair of diastereomeric 1:2 salts of (R)‐ and (S)‐2‐methylpiperazine with (2S,3S)‐tartaric acid, namely (R)‐2‐methylpiperazinediium bis[hydrogen (2S,3S)‐tartrate] monohydrate, (I), and (S)‐2‐methylpiperazinediium bis[hydrogen (2S,3S)‐tartrate] monohydrate, (II), both C₅H₁₄N₂²⁺·2C₄H₅O₆⁻·H₂O, each reveal the formation of well‐defined head‐to‐tail‐connected hydrogen tartrate chains; these chains are linked into a two‐dimensional sheet via intermolecular hydrogen bonds involving hydroxy groups and water molecules, resulting in a layer structure. The (R)‐2‐methylpiperazinediium ions lie between the hydrogen tartrate layers in the most stable equatorial conformation in (I), whereas in (II), these ions are in an unstable axial position inside the more interconnected layers and form a larger number of intermolecular hydrogen bonds than are observed in (I).     

Volatile ZnPhen(S2CNEt2)2 and MnPhen(S2CNEt2)2 complexes and the MnZn2Phen3(S2CNEt2)6 phase: Thermal behavior and crystal and molecular structures of two modifications of ZnPhen(S2CNEt2)2

Two crystal modifications, I and II, of the ZnPhen(S₂CNEt₂)₂ complex have been isolated. According to XRD data, the single crystals of I are triclinic with a=9.745(2), b=10.252(2), c=14.331(3) Å, α=99.18(2), β=91.01(2), γ=113.28(2)°, V=1293.2(4) ų, space group P1, Z=2, d_calc=1.401 g/cm³. The crystals of II are monoclinic with a=7.220(6), b=18.095(2), c=19.050(4) Å, β=95.85(2)°, V=2475.8(7) ų, space group C2/c, Z=4, d_calc=1.461 g/cm³. In both modifications, the structure is formed by monomer molecules with a distorted octahedral environment of the zinc atom. All atoms in I are in the general position; in II, the atoms are linked by the twofold rotation axis. It is shown by X-ray phase analysis (XRPA) that the MnPhen(S₂CNEt₂)₂ complexes (III) are isostructural to modification I of the ZnPhen(S₂CNEt₂)₂ complex, which underlies the synthesis of a solid solution of these complexes, MnZn₂Phen₃(S₂CNEt₂)₆ (phase IV). It is found that MPhen(S₂CNEt₂)₂ (M=Zn²⁺, Mn²⁺) and phase IV quantitatively sublime when heated in vacuum. Thermolysis of III in argon yields manganese(II) sulfide of cubic modification; the main product of thermolysis of phase IV is a solid solution of Zn_xMn_1?xS of hexagonal modification.     

Syntheses,characterizations, and crystal structures of organotin(IV) chloride complexes with 4,4′‐bipyridine

The organotin(IV) chlorides R_nSnCl_4−n (n = 3, R = Ph, PhCH₂, n−Bu; and n =2, R = n−Bu, Ph, PhCH₂) react with 4,4′‐bipyridine (4′4‐bpy) to give [(Ph₃SnCl)₂(4,4′‐bpy)_1.5(C₆H₆)_0.5] ( 1 ), [(PhCH₂)₃‐ SnCl]₂ (4,4′‐bpy) ( 2 ), [(n−Bu)₃SnCl]₂(4,4′‐bpy) ( 3 ), [(n−Bu)₂SnCl₂(4,4′‐bpy)] ( 4 ), [Ph₂SnCl₂(4,4′‐bpy)] ( 5 ), and [(PhCH₂)₂SnCl₂(4,4′‐bpy)] ( 6 ). The new complexes have been characterized by elemental analyses, IR, ¹H, ¹³C, ¹¹⁹Sn NMR spectroscopy. The structures of ( 1 ), ( 2 ), ( 4 ), and ( 6 ) have been determined by X‐ray crystallography. Crystal structures of ( 1 ) and ( 2 ) show that the coordination number of tin is five. In complex ( 1 ), two different molecules exist: one is a binuclear molecule bridged by 4,4′‐bpy and another is a mononuclear one, only one N of 4,4′‐bpy coordinate to tin. Complex ( 2 ) contains an infinite 1‐D polymeric binuclear chain by weak Sn…Cl intermolecular interactions with neighboring molecules. In the complexes ( 4 ) and ( 6 ), the tin is six‐coordinate, and the 4,4′‐bpy moieties bridge adjacent dialkyltin(IV)dichloride molecules to form a linear chain. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:338–346, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20016     

Synthesis and Crystal Structure of Bis[（2,6—pyridinedicar—boxylato）（methanol）dibenzyltion（Ⅳ）]

A novel seven‐coordinate dimer bis[(2,6‐pyridinedicarboxylato)(methanol)dibenzyltin(IV)] was synthesized by the reaction of (PhCH₂)₃SnCl with 2,6‐pyridine dicarboxylic acid in 1:1 molar ratio in methanol solution. The structure was characterized by elemental analysis, IR and ¹H NMR spectra, and the crystal structure was determined by X‐ray single crystal diffraction analysis. The crystal belongs to monoclinic space group P2₁/n, a =0.96250(19) nm, b = 1.0947(2) nm, c = 1.9965(4) nm, β = 92.31(3)°, Z = 2, V = 2.1019(7) nm³, D_c = 1.574 g/cm³, μ = 1.248 mm^?1, F(000)=1000, R₁ = 0.0675, wR₂ = 0.0836. In the crystals of the complex, each tin atom is seven‐coordinated in a distorted bipyramidal structure.