Synthesis, spectroscopic characterization and solution behavior of new tin tetrachloride adducts with g-keto allyl phosphonates (original) (raw)
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Journal of Molecular Structure, 2017
Four new octahedral complexes of the type [SnCl4L2] (L ¼ g-keto allyl phosphonate) (1e4) were prepared and characterized by multinuclear (1H, 13C, 31P and 119Sn) NMR, IR spectroscopy and elemental analysis. The NMR data show, as expected, that these complexes exist in solution as mixtures of cis and trans isomers. More importantly, the solution structure was confirmed by 119Sn NMR spectra which show two triplets corresponding to the two isomers. In addition, the solution behavior of these complexes in the presence of excess ligand was studied by variable temperature NMR using the coalescence temperature method. The metal-ligand exchange activation energies were therefore determined and found to be in the range 57e60 kJ/mol. The effect of remote substituents on the metal-ligand interaction was studied and compared with closely related tin-phosphoryl complexes.
Polyhedron, 1994
Reactions between methylenediphenylphosphinate anions [CH,P(E)Ph& (E = $0) and appropriate chlorophenyltin(IV) compounds in tetrahydrofuran afforded the organotin compounds [Ph,_.Sn(CH,P(S)Ph,)& (x = l-4) l&4 and [Ph,SnCl(CH, P(O)Ph,)],, 5. All compounds have been characterized structurally, l-4 as 4-coordinate monometallic species and 5 as a bimetallic S-membered metallacycle which is 5-coordinate at each metal atom.
Inorganic Chemistry, 2017
Materials and methods All operations were carried out using standard Schlenk line techniques under dry nitrogen atmosphere. Solvents were freshly distilled over phosphorus pentoxide (chloroform, dichloromethane and hexane) and over magnesium cake (methanol, ethanol). Glassware was dried in an oven at 110−120 °C and further flame-dried under vacuum prior to use. Commercial reagent grade tin powder (CDH, 325 mesh) was used without further purification. Allyl bromide, trimethyl phosphite, triethylphosphite and triisopropyl phosphite (Aldrich) were used as supplied. Methyl/allyl/2-thienyl/benzyl phosphonic acid diethyl ester and methylphosphonic acid di-isopropyl ester were prepared using literature methods 1-3 1 H, 13 C{ 1 H}, 31 P{ 1 H}, and 119 Sn{ 1 H} NMR spectra were recorded on a BRUKER DPX-300 spectrometer at 300, 75.48, 121.50, and 119.92 MHz, respectively. 1 H and 13 C chemical shifts are quoted with respect to the residual protons of the solvents (CDCl 3), while 31 P and 119 Sn NMR data are given using 85% H 3 PO 4 and tetramethyltin as the external standards, respectively. The solid state NMR spectra were recorded on a Bruker Avance II+ 600 NMR spectrometer operating at 600.11 MHz proton frequency (223.67 MHz for 119 Sn), using 4 mm solid state CP-MAS dual probe head. The samples were loaded in 4 mm zirconia rotors and
Polyhedron, 2006
Two octahedral complexes of the general formula SnCl 4 AE 2(O)PF 2 NR 2 (R = Me (1) or Et (2)) have been synthesised from SnCl 4 and the ligand R 2 NP(O)F 2 in anhydrous CHCl 3 . The new adducts have been characterised by multinuclear ( 119 Sn, 31 P, 19 F and 1 H) NMR, IR spectroscopy and elemental analysis. When compared with previously described hexamethylphosphoramide (HMPA) and trimethylphosphate (TMPA) analogues, the NMR data of the two complexes prepared suggest the presence of only the cis isomer in solution. Steric factors and the Lewis basicity of the ligand may explain the stereochemistry observed. Low temperature 31 P and 119 Sn NMR spectra show that the compounds partially dissociate in dichloromethane. Additionally, DFT/B3LYP calculations on complex 1 and its ligand have been carried out to support the interpretations of NMR data.
A Tin-119 NMR investigation of phosphine and phosphine oxide adducts of organotin chlorides
Journal of Organometallic Chemistry, 2001
The stoichiometry and structure of phosphine and phosphine oxide adducts of Ph 3 SnCl, R 2 SnCl 2 (R =Et, Pr, Bu, t-Bu, and Ph), and RSnCl 3 (R =Bu and Ph) were studied with Sn-119 spectroscopy. The shift of the Sn-119 resonance to a lower frequency upon adduct formation, the multiplicity of the resonance, the variation of P-31-Sn-119 coupling with the nature of the substituent, and the change in structure of the peaks with concentration and temperature were all used to determine stoichiometry and structure. The organotin chloride adducts readily exchange with base or with other adducts. The diorganotin dichlorides form only 1:1 adducts with tributylphosphine (TBP), even at high base to acid ratios, but most form 1:2 adducts (as several geometric isomers) with phosphine oxides at mole ratios above 1:1. The lower dialkyltin dichlorides prefer to form 1:1 adducts (at 1:1 mole ratios) with TBP rather than tributylphosphine oxide (TBPO), whereas diphenyltin dichloride and di(t-butyl)tin dichloride prefer TBPO adduct formation. The reactions of the trihalides with TBP and TBPO are complicated by aryl transfer or displacement of chloride by base and consequent ion formation.
Polyhedron, 2001
SnR 2 Cl 2 ] (R=Me, t Bu) react with OPPh 2 C 6 H 4 SH in the presence of NaOEt affording mononuclear derivatives [SnR 2 (OPPh 2 C 6 H 4 S) 2 ] (1, 2) with two units of the oxide of the thiophenylphosphine. The loss of one of such units is achieved by the reaction of 1 and 2 with HCF 3 SO 3 or HClO 4 giving rise to complexes with the formula [SnR 2 (OPPh 2 C 6 H 4 S)]A (A = CF 3 SO 3 , ClO 4 ) . The crystal structure of [Sn t Bu 2 (OPPh 2 C 6 H 4 S)]ClO 4 (4b) has been determined by X-ray diffraction.
Synthesis and characterization of tin tetrafluoride adducts with fluoroalkyl phosphoryl ligands
Journal of Fluorine Chemistry, 2013
The reaction of SnF 4 with (R 2 N) n P(O)(OCH 2 CF 3) 3Àn (n = 0-2) produces a series of new octahedral complexes of SnF 4 L 2 type (L = (R 2 N) 2 P(O)OCH 2 CF 3 ; R = Me (1); Et (2), L = R 2 NP(O)(OCH 2 CF 3) 2 ; R = Me (3); Et (4) or L = P(O)(OCH 2 CF 3) 3 (5)). The adducts have been characterized by multinuclear (19 F, 31 P and 119 Sn) NMR, IR spectroscopy and elemental analyses. The NMR data particularly the 19 F NMR spectra show the existence of complexes as mixtures of cis and trans isomers. The variable temperature NMR study in CH 2 Cl 2 solutions in the presence of excess ligand indicated that the ligand exchange at room temperature is slow for 1-4 and fast only for 5. The results were compared with those of SnCl 4 analogues and show the formation of higher trans ratios for the studied complexes.
Journal of the Brazilian Chemical Society, 2009
A reação do ligante ambidentado dibenzilsulfóxido (dbso) com Me 2 SnCl 2 na proporção molar 1:1 leva à formação do produto pentacoordenado [Me 2 SnCl 2 (dbso)], enquanto Ph 2 SnCl 2 leva à formação do complexo hexacoordenado trans-[Ph 2 SnCl 2 (dbso) 2 ], utilizando as mesmas condições de reação. Por outro lado, a reação com n Bu 2 SnCl 2 forma o produto bimetálico [{ n Bu 2 SnCl 2 (dbso)} 2 ], o qual provavelmente possui núcleos de estanho(IV) octaédricos e cloretos em ponte. Os complexos [MeSnCl 3 (dbso) 2 ] e [Ph 3 SnCl(dbso)] também foram preparados. Todos os produtos foram estudados por análise elementar e por espectroscopias no IV, RMN (1 H, 13 C, 119 Sn) e Mössbauer. As espécies hexacoordenadas fac-[MeSnCl 3 (dbso) 2 ] e trans-[Ph 2 SnCl 2 (dbso) 2 ] foram também estudadas por difratometria de raios X; as determinações estruturais revelaram que estes compostos cristalizam-se nos sistemas cristalinos ortorrômbico, Pbcn, e monoclínico, P2 1 /c, respectivamente. As moléculas possuem átomos de estanho(IV) numa geometria octaédrica distorcida, com os dois ligantes dbso em posições cis e trans, respectivamente. The reaction of the ambidentate ligand dibenzylsulfoxide (dbso) with Me 2 SnCl 2 in 1:1 molar ratio leads to the formation of the five-coordinate adduct [Me 2 SnCl 2 (dbso)], whereas the same reaction conditions with Ph 2 SnCl 2 provide the six-coordinate adduct trans-[Ph 2 SnCl 2 (dbso) 2 ]. On the other hand, the reaction with n Bu 2 SnCl 2 forms the dimeric adduct [{ n Bu 2 SnCl 2 (dbso)} 2 ], which probably possesses octahedral tin(IV) nuclei and bridging chlorides. The adducts [MeSnCl 3 (dbso) 2 ] and [Ph 3 SnCl(dbso)] were also prepared and included in the study. All complexes were studied by microanalysis and IR, NMR (1 H, 13 C and 119 Sn) and Mössbauer spectroscopies to investigate their structural properties. The six-coordinate species fac-[MeSnCl 3 (dbso) 2 ] and trans-[Ph 2 SnCl 2 (dbso) 2 ] were also studied by single crystal X-ray diffractometry. These compounds crystallize in the orthorhombic, Pbcn, and monoclinic space group P2 1 /c, respectively, as discrete neutral molecules with the tin(IV) atom in a distorted octahedral geometry and the two dbso ligands in cis and trans positions, respectively.