J. J. Zuckerman

Oxy and thio phosphorus acid derivatives of tin. 5. X-ray crystal and molecular structure of bis(O,O'-diisopropyl dithiophosphato)diphenyltin(IV), a monomeric, molecular, virtual polymer

Abstract : The position of the tin atom was obtained from a Patterson map, and found to lie on the special position 0,0,0 (the crystallographic center of symmetry). The positions of the non-hydrogen light atoms were located by a succession of block-diagonal least squares refinements followed by a difference Fourier synthesis. Subsequent cycles of least-squares refinement allowed the thermal parameters to vary isotropically, initially, and anisotropically in later stages, to yield an R-factor of 0.054 for all data. At this point, correction was made for the anomalous dispersion of tin, and the structure further refined before all non-methyl hydrogen atoms were located from a final difference Fourier synthesis. Refinement was concluded when shifts in all parameters were less than one-third of their corresponding standard deviation. The final R factor was 0.033 for the 2599 reflections included in the least-squares calculations and 0.0522 over all data.

Diorganotin halide carboxylates, thiocarboxylates and halide haloacetates

Abstract Twenty-eight diorganotin halide acetates, thioacetates, haloacetates and carboxylates, eighteen not previously reported, have been synthesized by the reaction between the diorganotin oxides and acid halides, and by transacyloxylation reactions between diorganotin halide acetates and carboxylic acids. Infrared in the 2000—200 cm-1 range, proton and carbon-13 NMR and tin-119m Mossbauer data are interpreted in terms of acetoxy-bridged, trigonal bipyramidal tin in the solid phase with depolymerization occurring in solution where a dynamic equilibrium between diorganotin dihalide and dicarboxylate species is rapidly established. A new infrared absorption also appears at 100–125 cm-1 to higher frequency of the vasym(CO2) which disappears on heating. A dimeric structure based upon four-membered Sn2O2 or Sn2OX rings in which carboxylate group oxygen atoms bridge tin atoms of a second molecule leaving the CO group free is proposed. The halide thioacetates are associated in the solid state but are monomeric in solution.

The crystal and molecular structure of trimethyltin(IV) chloride, a chlorine-bridged, linear polymer

Abstract The crystal and molecular structure of trimethyltin(IV) chloride has been determined by the heavy-atom technique, and refined to a final R value of 0.041 for 1375 independent reflections (2θ 2σ(I)) recorded at 138 ± 2 K on a Nonius CAD-4 counter diffractometer. The crystals are monoclinic with space group I2/c; a 12.541(8), b 9.618(11), c 11.015(11) A, β 92.62(7)°, Z = 8, Dcalcd 1.994 g cm−3. The needle crystals are composed of polymeric chains of chlorine atoms bridging non-planar trimethyltin(IV) units at unequal (2.430(2) and 3.269(2) A) distances. The zig-zag chains are bent at chlorine (angle SnCl Sn 150.30(9)°), but nearly linear at tin (angle ClSn Cl 176.85(6)°) to describe a distorted trigonal bipyramidal geometry at tin with the trimethyltin groups eclipsed. The interchain d(Sn Cl) distances are greater than 4.1 A. The angles carbon—tin—carbon (mean 117.1(3)°) are larger than tetrahedral, while the angles carbon—tin—chlorine (mean 99.9(2) A) are smaller, in accord with isovalent hybridization principles, but more severely distorted than in the gas-phase, monomeric structure. The tin—chlorine distance of 2.430(2) A is also longer than in the gas phase monomer, and the intermolecular contact of 3.269 A is shorter than in other organotin chloride bridged systems (sum of Van der Waals radii 3.85 A).

Synthesis and characterization of di-and triorganotin(IV) diethyldithiophosphinates. The crystal and molecular structure of bis(diethyldithiophosphinato)dimethyltin(IV), Me2Sn(S2PEt2)2

Abstract Bis(diethyldithiophosphinato)diorganotin(IV), R 2 Sn(S 2 PEt 2 ) 2 (R = Me, n-Bu, Ch 2 Ph, Ph) and diethyldithiophosphinatotriorganotin(IV), R 3 SnS 2 PEt 2 (R = Me, cyclo-C 6 H 11 , CH 2 Ph, Ph) were synthesized in nearly quantitative yield by reaction of organotin chlorides with sodium diethyldithiophosphinate. The compounds were characterized by infrared and 1 H NMR spectra and, in part, by mass and 119m Sn Mossbauer spectrosopy. The probable structure of the new compounds was inferred from the spectral data. The crystal and molecular structure of Me 2 Sn(S 2 PEt 2 ) 2 has been determined by X-ray diffraction. The compound is monoclinic space group C ′2/ c , with a 20.814(11), b 6.243(3), c 16.092(8) A, 105.42(8)°, Z = 4, D x 1.500 g cm −3 . The molecule exhibits a distorted tetrahedral environment around tin, with angles CSnC 123.74(4) and SSnS 80.6(2)°. The bond distances within the dithiophosphinato ligand are PS 1.961(2), PS 2.054(2), PC 1.825(10) and 1.787(8) A. The two tinsulfur distances SnS 2.476(2) and Sn ⋯ S 3.336(2) A indicate the presence of two covalent bonds with additional non-bonded tinsulfur interactions; the ligands can thus best be described as severely anisobidentate.

The crystal structure of dimethylphenyltin(IV) acetate

Dimethylphenyltin(IV) acetate, (CH3)2(C6H5)SnOC(O)CH3, crystallizes in the orthorhombic space group Pbca with a 10.068(3), b 15.065(7), c 14.976(5) A; Z = 8; V 2271(2) A3. The structure was determined from 1793 observed out of 2348 unique reflections and refined on an R factor of 0.034. The geometry at tin is trigonal bipyramidal, with the oxygen atom of the acetate and the carbonyl oxygen of the adjacent symmetry-related (12 + x, 12 − y, 1 − z) acetate occupying the axial positions of the trans-C3SnO2 polyhedron to result in a polymer whose backbone, formed by the repetition of SnOC(O) fragment, adopts a conformation that is closer to the zig-zag configuration of trimethyltin acetate than to the helical form of triphenyltin acetate.

Single crystal and molecular structure of methylphenyltin(IV) dichloride, intermediate between polymeric and monomeric R2SnCl2 structures

Abstract Methylphenyltin(IV) dichloride crystallizes with a roughly linear array of four in atoms, each tetrahedrally coordinated to two chlorine atoms, as well as to a methyl and a phenyl group. Each successive pair of tin atoms appears incipiently bridged by two chlorine atoms, there being tin to neighboring chloride distances of 3.4–3.8 A which, if shortened, would leave each successive pair of tin atoms doubly bridged by chlorine atoms. The structure is thus reminiscent of the one dimensional polymers formed by R 2 SnCl 2 (R  Me, Et).

Di-and triorganotin(IV) derivatives of 2-benzoylbenzoic acid

Abstract Six triorganotin(IV) 2-benzoylbenzoates, 2-C 6 H 5 C(O)C 6 H 4 CO 2 SnR 3 , where R = CH 3 , C 2 H 5 , n-C 3 H 7 , n-C 4 H 9 , c-C 6 H 11 and C 6 H 5 , two 2-benzoyl-3,4,5,6-tetrachlorobenzoates, 2-C 6 H 5 C(O)C 6 Cl 4 CO 2 SnR 3 , where R = CH 3 and C 6 H 5 and two di-organotin(IV) bis-2-benzoylbenzoates, [C 6 H 5 C(O)C 6 H 4 CO 2 ] 2 SnR 2 , where R = CH 3 and C 6 H 5 , are prepared by metathesis between the organotin(IV) chloride and the sodium salt of the acid in ethanol, by azeotropically distilling water from benzene solutions of the bis-triorganotin(IV) oxide and the parent acid, or from tiorganotin(IV) hydroxide and the parent acid. The products are solids, and, except for the trimethyltin(IV) derivatives, are soluble in common organic solvents. Other Group IV ester derivatives of 2-benzoylbenzoic acid, 2-C 6 H 5 C(O)C 6 H 4 CO 2 MR 3 (MR 3 = Si(CH 3 ) 3 , Ge(C 2 H 5 ) 3 and Pb(C 6 H 5 ) 3 ), were also synthesized. 119m Sn Mossbauer isomer shift ( IS ) values confirm the tin(IV) oxidation states and the ruadrupole splittings ( QS ) (3.04–3.54 mm s −1 ) and ϱ ( QS/IS ) values (2.16–2.70) specify higher than four-coordination at tin in the solid state. From the QS values of the diorganotin(IV) derivatives a point-charge model is used to calculate the carbon-tin-carbon angles. The magnitudes of these angles show that these derivatives adopt a trans -configuration in the solid, and that the triorganotin(IV) derivatives have equatorial-R 3 Sn groups which are approximately planar. Absence of a ν asym (SnC) mode in the infrared and a ν sym (SnC) mode in the Raman specifies the planitary of the (CH 3 ) 3 Sn group on its solid derivative, but not in solution. Both bands appear for the (CH 3 ) 2 Sn derivative, ruling out a strictly linear array. The ketonic and carboxylate carbon-oxygen stretching frequencies are assigned at ca. 1650 and 1600 cm −1 , respectively, and it is concluded that the ketone group is not coordinated to the tin atom. The high values for the carbonyl stretching frequencies of the organosiyl-and germyl derivatives reflect four-coordination. NMR coupling constants, | 2 J ( 119 SnC 1 H|, reflect than four-coordination for the tri and dimethyltin(IV) derivatives in solution. 119 Sn NMR chemical shifts are to lower field than tetramethyltin for the aliphatic derivatives, reflecting low coordination, but not for the triphenyl- and diorganotin(IV) derivatives. Only one resonance is observed, so the open and lactol forms, if both are present, must be in rapid equilibrium. Carbon-13 resonance for the keto- and carboxylate carbons of the organotin derivatives resemble those of the open and not the lactol forms of the parent materials. No ditin or other fragments characteristics of the oligomer are seen in the mass spectrum at 70 eV. The evidence specifies an associated solid with bridging carboxylate groups from the open-form of 2-benzoylbenzoate in which the ketonic carbonyl group is not involved in coordination to the tin atom. The triorganotin(IV) derivatives contain equatorial-R 3 Sn groups, and the diorganotin(IV) derivatives contain trans -R 2 Sn groups.

Oxy- and thio-phosphorus acid derivatives of tin(IV). The crystal and molecular structure of O-methylmethylphosphatotriphenyltin(IV)☆

Abstract O-Methylmethylphosphatotriphenyltin(IV) (II) is synthesized by treating stoichiometric amounts of O,O′-dimethylmonothiophosphatotriphenyltin(IV) (I) with mercury. The negative 119Sn chemical shift in solution relative to tetramethyltin for I corresponds to higher than four coordination (at tin) in solution. The values of the 119Sn Mossbauer isomer shift for I and II confirm the presence of tin as tin(IV). The magnitudes of the quadrupole splitting and the ratios of the QS to the IS of both compounds reveal that tin is higher than four coordinated. The solid state structure of II was determined by X-ray diffraction. The compound crystallized in the trigonal space group R 3 with a, b 31.433(15), c 10.259(3) A, V 8778.2 A3, Z = 18, Dx 1.56 g cm−3 at 138 K. In the solid state compound II exists as a highly symmetric cyclic hexamer in which planar trimethyltin(IV) groups are axially bridged by O-P-O linkages. The geometry about tin is trigonal bipyramidal with an axial O-Sn-O angle of 177.1(2)° and average C-Sn-C angle of 120.0(2)°. The structure of the hexameric ring is linear at tin but bent at phosphorus with an O-P-O angle of 117.1(2)°.

Di- and tri-organotin(IV) diphenyldithiophosphinates

Abstract Di- and tri-organotin(IV) diphenyldithiophosphinates, R 2 Sn(S 2 PPh 2 ) 2 (R  Me, n-Bu, Bz, Ph) and R 3 SnS 2 PPh 2 (R  Me, Cy, Bz, Ph) were prepared by reaction of the corresponding organotin chlorides or oxides with diphenyldithiophosphinic acid or its ammonium salt. All the compounds were characterized by IR and 1 H NMR spectra. For R 2 Sn(S 2 PPh 2 ) 2 (R  Me, Ph) and Ph 3 SnS 2 PPh 2 mass spectra and tin-119m Mossbauer spectra were also recorded. Monodentate bonding of the dithiophosphinic ligand and tetrahedral structures are proposed for the triorganotin derivatives, while in diorganotin compounds there appears to be distorted octahedral geometry around tin, with anisobidentate dithiophosphonic ligands.

Stannocenophanes. Ring-bridged di-h5-cyclopentadienyltin(II) derivatives of α,α-dicyclopentadienyl-ortho-, -meta- and -para-xylene

Abstract Three isomeric examples of a new class of stannocene (di- h 5 -cyclopentadienyltin(II)) derivatives are described in which the h 5 -cyclopentadienyl rings are linked through methylene bridges to a phenyl system. The ortho -, meta - and para -xylene derivatives are synthesized from the disodium salt of (phenylene- dimethylene)dicyclopentadienide with tin(II) chloride in THF. The products are air-sensitive, off-white powders, soluble in organic solvents, which show no definite melting points. Exposure to air gives the R 2 SnO derivative and ultimately tin(IV) oxide. Tin-119m Mossbauer data corroborate the tin(II) oxidation state, and parent molecular ions at m/e = 352 are recorded as the highest m/e value in the mass spectra. The action of h 5 -cyclopentadienyltin(II) chloride on the disodium salt gives meta -phenylenedimethylenedi- h 5 -cyclopentadienyltin(II) di- h 5 -cyclopentadiene. The meta -stannocenophane derivative also yields an infusible BF 3 adduct from the BF 3 etherate. Mossbauer quadrupole splittings for the ortho - and para -stannocenophanes are much larger (1.84 and 1.29 mm s −1 respectively) than for stannocene itself.