Gavin M. Spencer

Diorganotin 1,3-dithiole-2-thione-4,5-dithiolate compounds, R2Sn(dmit): the crystal structure of MePhSn(dmit)

Abstract Neutral diorganotin dmit compounds, R2Sn(dmit), have been synthesised from R2SnX2 (R  Me, Et, Bu, octyl, Ph or o-MeOC6H4; R2  Ph,Me; X  Cl or Br) and [NEt4]2[Zn(dmit)2] (H2-dmit = 4,5-dimercapto-1,3-dithiole-2-thione , H2C3S5). Solution and solid state NMR spectra have been obtained for selected R2Sn(dmit) species as has the crystal structure of MePhSn(dmit) 10. Molecules of 10 in the solid state are linked into zig-zag chains via Sn · · · thione S intermolecular associations (SnS(51)= 3.139(1) A; SnS(51)C(31) = 111.2(2)°). The links between the monomers within the chains are further strengthened by weak S · · · S intermonomer interactions, S(51) · · · S(2) = 3.315(2) and S(31) · · · S(2) = 3.446(2) A. Furthermore, weaker S · · · S interactions (S(51) · · · S(111) = 3.635(2) A. link the chains. The geometry at tin is distorted trigonal bipyramidal; with the equatorial sites occupied by the organic groups (SnC = 2.111(5) and 2.134(2) A) and by a dithiolato sulphur atom (SnS(2) = 2.437(1) A). The axial sites are occupied by the other dithiolato sulphur atom (SnS)(1) = 2.487(1) A) and the bridging thione sulphur (S(51)): the valency angle, S(51)SnS(1), is 161.63(3)° with the dithiolate bite angle of 89.92(4)°. The R2Sn(dmit) compounds react with onium halides, [Q]X to give [Q][R2Sn(dmit)X], form complexes, [R2Sn(dmit)L], with donors, (e.g. L = bipy, py or DMF),and undergo exchange reactions with R21SnCl2.

Preparation of [tris(1,3-dithiole-2-thione-4,5-dithiolato)antimonate(1−)] complexes, [Sbv(dmit)3]−. Crystal structure of the 1,4-dimethylpyridinium salt

Abstract Ionic complexes, [Q] [Sb(dmit) 3 ] [Q = 1,4-Me 2 -pyridinium of NEt 4 ], have been isolated from the reaction of [Q] 2 [Zn(dmit) 2 ] and SbI 5 , prepared in situ from SbI 3 and I 2 (H 2 -dmit = 4,5-dimercapto-1,3-dithiole-2-thione). A crystal structure determination of [1,4-Me 2 -pyridinium] [Sb(dmit)] revealed that the anions contain octahedral Sb atoms, with SbS bond lengths between 2.504(1) and 2.553(1) A. The chelate bite angles are in the range 80.30(4)–83.50(5)°. Sulfur-sulfur contacts, at distances less than the van der Waals radii, link the anions into a 3-D (three-dimensional) framework: each of the three dmit ligands in an anion have weak S−−−S interactions with neighboring anions.

Main group metal 1,3-dithiole-2-thione-4,5-dithiolate (DMIT) compounds: II. Synthesis and structures of tetrabutylammonium butyl- and phenyl-bis(1,3-dithiole-2-thione-4,5-dithiolato)stannates, [Bu4N][RSn(DMIT)2] (R Bu or Ph)

Abstract Structures have been determined for [BU4N][RSn(DMIT)2] (III; R  Bu and IV; R = Ph), obtained from [Bu4N]2[Zn(DMIT)2] and RSnCl3. These complexes are isostructural. In the spirocyclic anions, the tin atoms are pentacoordinate and have geometries between trigonal bipyramidal (TBP) and rectangular pyramidal: the distortions away from TBP geometry are calculated to be ca 48 and 70% for II and IV respectively. The S atoms in the chelate ligands form the quasi-basal planes with the R groups in axial sites. The DMIT ligands, while individually planar, are not coplanar: the angles between the DMIT mean planes are 19.2 and 10.8° for III and IV respectively. The anions are packed side by side in the c direction with S … S separations close to the sum of the van der Waals radii. In the a and b directions, there are arrays of alternating cation and anion units.

Organotin-DMIT complexes : crystal structure of [Bu4N][Me2SnCl(DMIT)]

Abstract Various organotin-DMIT complexes have been prepared from organotin halides and [Bu 4 N] 2 [Ni(DMIT) 2 ] (H 2 -DMIT = 4,5-dimercapto-1,3-dithiole-2-thione). The crystal structure of [Bu 4 N][Me 2 ClSn(DMIT)] (V, R = Me) is reported: the compounds contains a trigonal bipyramidal tin atom in the anion.

Syntheses and properties of the lead 1,3-dithiole-2-thione-4,5-dithiolate (dmit) compounds: Ph2Pb(dmit), [Q] [Ph2Pb(dmit) I] [Q = NEt4 or 1,4-Me2-pyridinium], (Ph3Pb)2 (dmit) and Pb(dmit)

Abstract Syntheses of Ph 2 Pb(dmit) ( 3 ), [Q] [Ph 2 Pb(dmit)I] ( 5 , Q = NEt 4 or 1,4-Me 2 -pyridinium), (Ph 3 Pb) 2 (dmit) ( 4 ) and Pb(dmit) ( 6 ) are reported [H 2 -dmit = 4,5-dimercapto-1,3-dithiole-2-thione]. Compound 3 was produced from Ph 2 Pb(OAc) 2 and [NEt 4 ] 2 [Zn (dmit) 2 ], while 4 was obtained from Ph 3 PbOAc and either Na 2 (dmit) or [NEt 4 ] 2 [Zn(dmit) 2 ]. The ionic species, 5 , were obtained by addition of [Q] I to 3 ( eg. for Q = 1,4-Me 2 -pyridinium) or from reaction of Ph 2 PbI 2 with [NEt 4 ] 2 [Zn(dmit) 2 ]. Reaction of either Pb(OAc) 2 or Pb(NO 3 ) 2 with [NEt 4 ] 2 [Zn(dmit) 2 ] produced 6 . NMR spectra, including the solid state spectra for 3 , have been obtained. X-ray crystallography revealed 4 to be a monomeric compound with each Pb atom having a distorted tetrahedral geometry. The CPbS bond angles are less and the CPbC bond angles greater than ideal tetrahedral angles. The dmit ligand is effectively inserted between two phenyl rings of different Ph 3 Pb groups in 4 , with short non-bonded CC and CS distances of 3.4–3.7 A. Cyctic voltammetric studies of 3 and of 4 in DMF have also been carried out.

The molecular and crystal structure of tetraphenylphosphonium antimony(III) bis-dmit. A comparison with similar complexes

The molecular and crystal structure of tetraphenylphosphonium antimony(III) bis-dmit (H2-dmit 4,5-dimercapto-1,3-dithiole- 2-thione) has been determined by X-ray diffraction. The structure was solved by Patterson methods. The least-squares refinements lead to the conventional R factor of 0.039. A conformational characterization is reported for an almost undistorted pentagonal bipyramidal coordination about the Sb metal center, achieved through intraanionic and secondary interanionic bond interactions between antimony and thiocarbonyl sulfur atoms. The anions form a linear polymeric association elongated in the c direction.

[Bis(1,3-dithiole-2-thione-4,5- dithiolato)diarylantimonate(1-)], [Ar2Sb(dmit)2]−, complexes. Crystal structures of [NEt4][Ar2Sb(dmit)2] (Ar = Ph or p-tolyl)

Abstract The ionic complexes [Q][Ph2Sb(dmit)2] (4; Q = NEt4 or 1,4-Me2-pyridinium) and [Net4][(p-tolyl)2Sb(dmit)2] (5) have been prepared from [Q]2Zn(dmit)2] and Ar2SbCl3 in the presence of KSCN (H2-dmit = 4,5-dimercapto-1,3-dithiole-2-thione). As shown by X-ray crystallography for 4 (Q = NEt4) and 5, these complexes contain distorted octahedral anions with cis-aryl groups: The CSbC angles in 4 (Q = NEt4) and 5 are 93.1(2) adn 95.3(5)°, respectively. The dmit chealtes are unsymmetrically bonded to antimony in both 4 (Q = NEt4) and 5 with the longer bonds trans to the aryl groups (for both compounds, the SbS bond lengths are in the ranges, 2.614 to 2.636 and 2.530–2.550 A).

Addition of sulphenyl halides to alkenyl-metal compounds: III. Arenesulphenyl chloride additions to triethoxy- and triphenylvinylsilanes and to triphenylvinylgermanium. Crystal structure of (4-Me-2-O2NC6H3S)CH(SiPh3)CH2Cl

Abstract Additions of arenesulphenyl chlorides ( e.g. ArSCI  p -XC 6 H 4 SCl; X  Me or Cl; 4-Y-2-O 2 NC 6 H 4 SCl; Y  H, Me or NO 2 ) to R 3 MCHCH 2 [R 3 MPh 3 Si, (EtO) 3 Si or Ph 3 Ge] can provide both possible adducts: R 3 MCHSArCH 2 Cl (the anti -Markovnikov adducts) and R 3 MCHClCH 2 SAr (the Markovnikov adducts). In reactions in CH 2 Cl 2 at room temperature, the former adducts always dominate ( > 77%) and can be the exclusive products. The ratio of [R 3 MCHSArCH 2 Cl]:[R 3 MCHClCH 2 SAr increases in the sequences Ar  p -ClC 6 H 4 > o -O 2 NC 6 H 4 > 2,4-(O 2 N) 2 C 6 H 3 ; (Me 3 SiCHCH 2 ) > Ph 3 SiCHCH2 > (EtO) 3 SiCHCH2; and Ph 3 SiCHCH 2 > Ph 3 GeCHCH 2 . A crystal structure determination of (4-Me-2-O 2 NC 6 H 3 S)CH(SiPh 3 )CH 2 Cl revealed a slightly distorted tetrahedral geometry about Si with a staggered conformation about the central CC bond (SiCCCl dihedral angle is 167°). There is a short S ⋯ O intramolecular distance of 2.781 A.

Preparations and crystal structures of Sn(CH2CH2CO2Me)2(C3S5) and [Q][Sn(CH2CH2CO2Me)(C3S5)2](Q = NEt4 or 1,4-dimethylpyridinium, C3S5= 4,5-disulfanyl-1,3-dithiole-2-thionate)

The compounds Sn(CH2CH2CO2Me)2(C3S5)1(R = Me or Pri) and [Q][Sn(CH2CH2CO2Me)(C3S5)2]2(Q = NEt4 or 1,4-dimethylpyridinium; C3S5= 4,5-disulfanyl-1,3-dithiole-2-thionate) have been prepared and characterised by solution and solid-state NMR spectroscopy. A crystal structure determination of 1(R = Me) revealed it to be a monomeric six-co-ordinate, distorted-octahedral complex with chelating MeO2CCH2CH2 groups and trans-carbon atoms [Sn–O(C) 2.629(7)A]. The MeO2CCH2CH2 group in 2, both in solution and in the crystal, is monodentate: the tin centres in the anions of both complexes 2 were shown to have structures closer to rectangular pyramids than to trigonal bipyramids. There were, however, slight differences in the solid-state structures of the anions, particularly in regard to the separations of the Sn and carbonyl oxygen atoms; Sn ⋯ O intramolecular distances are 4.84(1) and 3.371(4)A in 2(Q = NEt4) and 2(Q = 1,4-dimethylpyridinium) respectively. There were also differences in the packing of the anions.