A. Sánchez González

Organotin compounds with 2,2′-biimidazole derivatives. The crystal structure of dibromo(N,N′-dimethyl-2,2′-biimidazole)dimethyltin(IV)

The compounds [SnMe2Br2(DMBIm)], [(SnMe2X2)2(DMBIm)] and (NEt4)2[(SnMe2X3)2(DMBIm)] (X  Cl or Br; DMBIm = N,N′-dimethyl-2,2′-biimidazole) have been synthesized and characterized by conductivity measurements and IR and 1H NMR spectroscopy. The structure of dibromo(N,N′-dimethyl-2,2′-biimidazole)dimethyltin(IV) was determined by X-ray diffraction. Crystals are: orthorhombic, P212121, with a 9.402(2), b 10.389(3), c 16.228(3) A, V 1585 A3, Z = 4. The structure was refined to R = 0.047 based on 1461 observed intensities. The compound consists of discrete [SnMe2Br2(DMBIm)] molecules in which the tin atom is octahedrally six-coordinate with trans methyl groups and bidentate DMBIm. IR data for [(SnMe2X2)2(DMBIm)] complexes are consistent with coordination number 5, and those for (NEt4)2[(SnMe2X3)2(DMBIm)] with coordination number 6 for the tin atom. The 1H NMR spectra show that the compounds undergo extensive dissociation in CDCl3.

The crystal structure of dichlorobis(imidazole)dimethyltin(IV)

Abstract The structure of dichlorobis(imidazole)dimethyltin(IV) has been determined by X-ray diffraction. The crystal consists of discrete trans -Me 2 SnCl 2 (HIm) 2 units with the metal atom octahedrally coordinated to two Cl atoms (SnCl, 2.5955(7) A; ClSnCl, 180°), two methyl carbons (SnC, 2.110(3) A; CSnC, 180°), and two imidazole groups (SnN, 2.312(2) A; NSnN, 180°). The imidazole ligands are bound to the metal through their pyridine-like nitrogen atom, and intermolecularly hydrogen-bonded to the chlorine atoms.

Preparation, characterization and crystal structure of tetrakis[1-methyl-2(3H)-imidazolinethione] dimethyltin(IV) nitrate

Abstract The synthesis and characterization (IR, 1 H and 119 Sn NMR, and mass spectra) of [SnMe 2 (Hmimt) 4 ](NO 3 ) 2 (Hmimt=1-methyl-2(3 H )-imidazolinethione) are described. The crystal structure has been determined by X-ray crystallography and refined to R =0.044, using 2277 observed reflections. The compound is triclinic, space group P 1 , with a =10.733(2), b =10.008(2), c =7.594(2) A, α=110.49(3), β=104.71(3) and γ=82.60(3)°. The tin atom is octahedrally coordinated and lies on a crystallographic inversion centre. The Hmimt ligand, bound via the S atom (the mean of the two independent Sn-S distances is 2.735 A), maintains its thione form in the complex. The nitrate ions are involved in hydrogen bonding with the NH groups of the ligands.

Organotin complexes with 1-methyl-2(3H)-imidazolinethione. The crystal structure of dichloro[1-methyl-2(3H)-imidazolinethione]dimethyltin(IV)

Abstract The compounds [SnMe 2 X 2 (Hmimt)], [SnMe 2 X 2 (Hmimt) 2 ] and (Et 4 N)[SnMe 2 X 3 (Hmimt)] (X = Cl or Br; Hmimt = 1-methyl-2(3 H )-imidazolinethione) have been prepared and characterized by conductivity measurements and by IR, Raman, Mossbauer and 1 H, 13 C and 119 Sn NMR spectroscopy. The structure of [SnMe 2 Cl 2 (Hmimt)] was determined by X-ray diffraction. Its crystals are triclinic, space group P 1 , with a 9.702(2), b 9.375(2), c 7.119(1) A,α 68.1(2),s 86.6(2), γ 85.6(2)°, U 598.7 A 3 , Z = 2, R = 0.062, R w = 0.058 and consist of chlorine-bridged [SnMe 2 Cl 2 (Hmimt)] dimers in which the hexacoordinate tin atoms have distorted octahedral environments and the thiones are S-bonded. Neighbouring dimers are linked by NH … Cl bonds. Mossbauer and vibrational data suggest octahedral coordination for the tin atom in [SnMe 2 X 2 (Hmimt) 2 ] and (Et 4 N)[SnMe 2 X 3 (Hmimt)].

Diorganotin dihalide complexes of N‐bidentate ligands: crystal structures of diethyldibromo‐ and dibutyldichloro[bis(1‐methyl‐2‐imidazolylthio)methane]tin(IV)

The compounds [SnR 2 X 2 (bmimt)] (R= Me, Et, Bu; X = Cl, Br; bmimt = bis(1-methyl-2-imidazolylthio)methane) have been prepared and characterized by conductivity measurements and by IR, Raman, mass, Mossbauer and 1 H NMR spectroscopy. The structures of the diethyldibromo- and dibutyldichlorotin(IV) derivatives were determined by X-ray crystallography. The crystals consist of two slightly different types of discrete [SnR 2 X 2 (bmimt)] unit with the metal atom octahedrally coordinated to the two halogen atoms, two alkyl carbons and the two nonmethylated nitrogen atoms of the ligand. This coordination mode, which the spectroscopic data suggest is also present in all the other complexes studied, results in the formation of an eight-membered CS 2 C 2 N 2 Sn ring. The Sn-N distances in [SnEt 2 Br 2 (bmimt)] (2.53 and 2.42 A) and [SnBu 2 Cl 2 (bmimt)] (2.52 and 2.47 A ), suggest that these compounds may have antitumour activity

Organotin compounds with 1-methyl-2(3H)-imidazolinethione. The crystal and molecular structure of dichlorobis[1-methyl-2(3H)-imidazolinethione]diphenyltin(IV)

The compounds [SnPh 2 Cl 2 (Hmimt)], [SnPh 2 Cl 2 (Hmimt) 2 ] and (Et 4 N)[SnPh 2 Cl 3 (Hmimt)] (Hmimt=1-methyl-2(3H)-imidazolinethione) have been prepared and characterized by conductivity measurements and by IR, Raman, mass, Mossbauer and 1 H, 13 C, and 119 Sn NMR spectroscopies. The structure of the all-trans-octahedral [SnPh 2 Cl 2 (Hmimt) 2 ] complex was determined by X-ray crystallography. Coordination bond lengths (A) are: Sn-Cl 2.587(1), Sn-C 2.154(3) and Sn-S 2.705(1)

Thiazole complexes of diorganotin(IV) dihalides: the crystal structure of dichlorodiphenylbis(thiazole) tin(IV)

Abstract The reaction of thiazole (Tz) with diorganotin(IV) dihalides yielded compounds of type [SnR 2 X 2 (Tz) 2 ] (R = Me, Et, Ph; X = Cl, Br). The structure of dichlorodiphenylbis(thiazole)tin(IV) was determined by X-ray diffraction. The crystals are monoclinic (space group P 2 1 / c ) and consist of discrete trans -SnPh 2 Cl 2 (Tz) 2 units with the metal atom coordinated to two Cl atoms, two phenyl carbons, and the N atoms of two thiazole rings. Mossbauer and IR spectra suggest similar trans-stereochemistry for the other complexes prepared. The behavior of these compounds in solution was studied by conductimetry and NMR techniques.

Complexes of diethyldihalotin (IV) with imidazole and pyrazole. The crystal structure of dibromobis (pyrazole) diethyltin (IV)

Abstract A series of neutral adducts of dimethyltin(IV) dihalides of general formula Me2SnX2L2 (where L = imidazole, pyrazole) has been prepared. The structure of the complex dibromobis(pyrazole)dimethyltin(IV) has been determined by X-ray diffraction. (Crystal data: Br2C8H14N4Sn, M = 444.7; orthorhombic, Pbca, a 7.644(1), b 13.955(7), c 26.249(4) A, V 2800(2) A3, Z = 8, R = 0.041). The compound consists of discrete trans-SnMe2Br2(HPz)2 units with the metal atom octahedrally coordinated to two Br atoms (SnBr 2.703(2), 2.766(2) A; BrSnBr 178.78(7)°), to two methyl carbons (both SnC 2.13(2) A; CSnC 179.0(6)°), and to two pyrazole groups (SnN 2.34(1), 2.36(1) A; NSnN 175.8(4)°). The dihedral angle between the two pyrazole rings is 8.9°. The IR data are consistent with this trans-stereochemistry for all the complexes. The 1H NMR data indicate that the pyrazole compounds dissociate in DMSO-d6 solution but in CDCl3 solution the trans-configuration can be also present if an excess of the ligand is present.

Synthesis, characterization and crystal structure of (C3H5N2)2[Sn2(NO3)4−(μ-OH)2Me4], a di-μ-hydroxo-bridged compound with heptacoordinated tin(IV)

Abstract [Sn2(NO3)2(μ-OH)2Me4] reacts with imidazole in nitric acid media to give (C3H5N2)2[Sn2(NO3)4(μ-OH)2Me4], the structure of which was determined by X-ray diffraction and refined to R=0.032 using 1711 observed reflections. The compound is monoclinic, space group P21/c, with a=9.315(1), b=16.107(5), c=8.147(2) A, β=101.94(1)°, Z=2. The crystal consists of imidazolium [C3H5N2]+ cations and [Sn2(NO3)4(μ- OH)2Me4]2− anions with the imidazolium rings hydrogen- bonded to nitrate groups of neighbouring units and to the hydroxyl bridging groups of the anion. Each hydroxyl group is also hydrogen bonded to one nitrate group of a neighbouring anion. In the anion each tin atom is seven-coordinated to two methyl groups, one asymmetrically bidentate nitrate anion, one monodentate nitrate anion and two bridging hydroxyl groups. IR and Mossbauer data are discussed on the basis of the above coordination scheme.

Complexes of dibutyldihalotin(IV) with imidazole and pyrazole. The crystal structure of dibutyldichlorobis(pyrazole)tin(IV)

Abstract Complexes of the type [SnBu2X2L2] (X=Cl or Br; L=HIm or HPz) were obtained from the reaction of SnBu2X2 with imidazole (HIm) or pyrazole (HPz). The structure of dibutyldichlorobis (pyrazole)tin(IV) was determined by X-ray diffraction. The crystal consists of discrete all-trans SnBu2Cl2(HPz)2 units with the metal atom octahedrally coordinated to two butyl carbons, two Cl atoms and two pyrazole rings. The pyrazole ligands are bound intra- and inter-molecularly to the chlorine atoms. IR data suggest similar trans-stereochemistry for the other compounds prepared. The 13C NMR spectra indicate that [SnBu2X2(HPz)2] dissociates completely in DMSO-d6 but only partially in CDCl3.