Synthesis and characterization of diorganotin(IV) derivatives of 2-mercaptopyridine and crystal structure of diphenyl pyridine-2-thiolatochlorotin(IV)

Di-tert-butyltin(IV) 2-pyridyl and 4,6-dimethyl-2-pyrimidyl thiolates: versatile single source precursors for the preparation of SnS nanoplatelets as anode material for lithium ion batteries

New air and moisture stable di-tert-butyltin complexes derived from 2-mercaptopyridine (HSpy), [^tBu₂Sn(Spy)₂], [^tBu₂Sn(Cl)(Spy)] and 4,6-dimethyl-2-mercaptopyrimidine (HSpymMe₂) [^tBu₂Sn(Cl)(SpymMe₂)], have been prepared and utilized as single-source molecular precursors for the preparation of orthorhombic SnS nanoplatelets by a hot injection method and thin films by aerosol assisted chemical vapour deposition (AACVD). The complexes were characterized by NMR (¹H, ¹³C, ¹¹⁹Sn) and elemental analysis and their structures were unambiguously established by the single crystal X-ray diffraction technique. Thermolysis of these complexes in oleylamine (OAm) produced SnS nanoplatelets. The morphologies, elemental compositions, phase purity and crystal structures of the resulting Oam-capped nanoplatelets were determined by electron microscopy (SEM, TEM), energy dispersive X-ray spectroscopy (EDS) and pXRD, while the band gaps of the nanoplatelets were evaluated by diffuse reflectance spectroscopy (DRS) and were blue shifted relative to the bulk material. The morphology and preferential growth of the nanoplatelets were found to be significantly altered by the nature of the molecular precursor employed. The synthesized SnS nanoplatelets were evaluated for their performance as anode material for lithium ion batteries (LIBs). A cell comprised of an SnS electrode could be cycled for 50 cycles. The rate capability of SnS was investigated at different current densities in the range 0.1 to 0.7 A g^-1 which revealed that the initial capacity could be regained.

Synthesis and Oxidation of a Paddlewheel-Shaped Rhodium/Antimony Complex Featuring Pyridine-2-Thiolate Ligands

The paddlewheel-shaped complex [Sb(μ-pyS)₄ Rh]₂ (1) (pyS^- = 2-S-C₅ H₄ N^- ) was synthesized from [Rh(pyS)(cod)]₂ (cod=1,5-cyclooctadiene) and Sb(pyS)₃ . Upon oxidation with ONMe₃ , the complex [(μ-O)Sb(μ-pyS)₃ Rh(κ² -pyS)]₂ (2) is formed. Both 1 and 2 form dimers and feature short Rh-Sb bonds and bridging pyS ligands. ¹²¹ Sb Mössbauer spectro- scopy and computational studies were employed to elucidate the Rh-Sb bonding in 1 and 2. Both covalent (Rh-Sb, X-type Sb ligand) and dative (Rh→Sb, Z-type; Rh←Sb L-type Sb ligand) interactions have to be considered for the description of their bonding situations.

Diorganotin(iv) 4,6-dimethyl-2-pyrimidyl selenolates: synthesis, structures and their utility as molecular precursors for the preparation of SnSe2 nano-sheets and thin films

Organotin complexes, [R₂Sn{SeC₄H(Me-4,6)₂N₂}₂] and [R₂SnCl{SeC₄H(Me-4,6)₂N₂}] (R = alkyl) were prepared and utilized as ssps for the preparation of SnSe₂ nanosheets and thin films. Tunability of band gaps has been demonstrated.

Diorganotin(iv) 2-pyridyl and 2-pyrimidyl thiolates: synthesis, structures and their utility as molecular precursors for the preparation of tin sulfide nanosheets

Organotin complexes, [R₂Sn(2-SC₅H₄N)₂] and [R₂SnCl{SC₄H(Me-4,6)₂N₂}] (R = Me, Et) were prepared, characterized and utilized as ssps for the preparation of SnS nanosheets. The direct/indirect band gaps of the latter were evaluated.

Neutral six-coordinate and cationic five-coordinate silicon(IV) complexes with two bidentate monoanionic N,S-pyridine-2-thiolato(-) ligands

A series of neutral six-coordinate silicon(IV) complexes (4-11) with two bidentate monoanionic N,S-pyridine-2-thiolato ligands and two monodentate ligands R(1) and R(2) was synthesized (4, R(1) = R(2) = Cl; 5, R(1) = Ph, R(2) = Cl; 6, R(1) = Ph, R(2) = F; 7, R(1) = Ph, R(2) = Br; 8, R(1) = Ph, R(2) = N3; 9, R(1) = Ph, R(2) = NCO; 10, R(1) = Ph, R(2) = NCS; 11, R(1) = Me, R(2) = Cl). In addition, the related ionic compound 12 was synthesized, which contains a cationic five-coordinate silicon(IV) complex with two bidentate monoanionic N,S-pyridine-2-thiolato ligands and one phenyl group (counterion: I(-)). Compounds 4-12 were characterized by elemental analyses, NMR spectroscopic studies in the solid state and in solution, and crystal structure analyses (except 7). These structural investigations were performed with a special emphasis on the sophisticated stereochemistry of these compounds. These experimental investigations were complemented by computational studies, including bonding analyses based on relativistic density functional theory.

X-ray structure of and refinement strategy for disordered triphenyl(2-pyridinethiolato)tin(IV): [Ph3Sn(2-pyS)]

The crystal and molecular structure of disordered triphenyl(pyridine-2-thiolato)tin(IV), [Ph3Sn(2-pyS)], C23H19NSSn, has been determined at room temperature. The colorless crystals are monoclinic, space group C2/c with unit cell dimensions a = 17.179(5) Å, b = 15.256(1) Å, c = 8.142(5) Å, β = 109.55(3)°, Z = 4 and Dx = 1.520 Mgm−3. A molecule of [Ph3Sn(2-pyS)] with half occupancy comprises the asymmetric unit and this molecule is 1:1 disordered about the 2-fold rotation axis with the Sn 0.38 Å off axis. Constrained refinement using 95 variables plus additional restraints gave a final R = 0.046 for 1608 reflections with I ≥ 3.0σ(I). The title compound is molecular and features a distorted tetrahedral tin-atom geometry defined by a thiolate S(2) atom [Sn–S 2.456(3) Å] and three phenyl groups; distortion from the ideal geometry can be traced, in part, to the close approach of the pyridine-N atom, i.e. Sn–N(l) is 2.831(6) Å.

DFT Calculations of the Electric Field Gradient at the Tin Nucleus as a Support of Structural Interpretation by119Sn Mössbauer Spectroscopy

DFT calculations, using an all-electron basis set and with full geometry optimization, were performed on 34 Sn(II) and Sn(IV) compounds of known structure and (119)Sn Mössbauer parameters, to obtain the theoretical values of the electric field gradient components, V(xx), V(yy), and V(zz), at the tin nucleus. These were used to determine the quantity V = V(zz)[1+ 1/3((V(xx) - V(yy))/((V(zz))(2)](1/2), for each investigated compound, which is related to the quadrupole splitting (DeltaE) parameter according to DeltaE = 1/2eQV, where e is the electronic charge and Q is the quadrupole moment of the tin nucleus. The linear fitting of the correlation plot of the experimental DeltaE, versus the corresponding calculated V values, produced a slope that is equal to 0.93 +/- 0.03 and a correlation coefficient R = 0.982. The value of Q obtained, 15.2 +/- 4.4 fm(2), is in agreement with that previously experimentally determined or calculated by analogous procedures. The calculation method is able to establish the sign of the electric field gradient component V(zz), in agreement with the sign of DeltaE determined experimentally by Mössbauer-Zeeman spectroscopy. The calculated structural parameters are in good agreement with the corresponding experimental data, determined by X-ray crystallography in the solid state, with average structural deviations of about 3 % for bond lengths and angles in the tin environment. Calculated values of DeltaE were obtained from the calibration fitting constant and from the values of V. By comparing experimental and calculated DeltaE parameters, the structure assignment of configurational isomers was successful in two test cases, in agreement with the experimental X-ray crystallographic structures. These results indicate that the method can be used as a tool to support the routine structure interpretation of tin compounds by (119)Sn Mössbauer spectroscopy.

A new method of syntheses of 18-membered macrocyclic diphenyltin(IV) compounds and crystal structures of {Ph2Sn[S(C6H3NO)O]}3·Y (Y = 2H2O or 4C6H6) and {Ph3Sn[S(C6H3NO)O]SnPh3(EtOH)}·[EtOH]

Two diphenyltin(IV) compounds: {Ph2Sn[S(C6H3NO)O]}3·Y (Y = 2H2O, 1; 4C6H6, 2) have been unexpectedly obtained by the reactions of triphenyltin chloride with 2-mercaptonicotinic acid in the presence of Et3N. However, by the reaction of the same reactants in the presence of EtONa, only a new triphenyltin(IV) compound ({Ph3Sn[S(C6H3NO)O]SnPh3(EtOH)}·[EtOH], 3) was obtained. The X-ray analyses reveal that compounds 1 and 2 are trinuclear, 18-membered macrocyclic compounds while 3 is a dinuclear compound. Specially, π-π stacking interaction was recognized in crystals of compound 1, which makes it a dimer. Co-crystallization was found in the crystals of all the three compounds 1, 2, and 3, the co-crystallized solvent molecules are water, benzene, and ethanol molecules, respectively. A possible dephenylation mechanism of 1 and 2 was illustrated in detail.Key words: triphenyltin, 2-mercaptonicotinic acid, dephenylation, macrocyclic, π-π stacking interaction, co-crystallization, crystal structure.

Syntheses, characterization, and X-ray crystal structures of diorganotin(IV) derivatives of 2-pyridinethiolato-N-oxide

The diorganotin(IV) dichloride reacts with sodium 2-pyridinethiolato-N-oxide in a 1:1 ratio to produce [Me2SnCl(2-SpyO)] (1), [Et2SnCl(2-SpyO)] (2), [Bu2SnCl(2-SpyO)] (3), [Ph2SnCl(2-SpyO)] (4), and [(PhCH2)2SnCl(2- SpyO)] (5). The new complexes have been characterized by elemental analysis and IR and NMR (1H, 119Sn, and 13C) spectroscopy. On the basis of 119Sn NMR data the effective coordination number in solution is five. The structures 1 and 4 have been confirmed by X-ray crystallography. Crystals of 1 are triclinic with space group P[Formula: see text] and those of 4 are monoclinic, P21/n. The tin environment is a distorted trigonal bipyramid with the Cl and oxygen atoms in apical positions. Both complexes exhibit strong π–π stacking interactions. Key words: diorganotin, π–π stacking interaction, 2-pyridinethiolato-N-oxide, crystal structure.