The interaction of organotin(iv) acceptors with 1,4-bis(5-hydroxy-1-phenyl-3-methyl-1H-pyrazol-4-yl)butane-1,4-dioneCoordination chemistry of bis(pyrazolones): a rational design of nuclearity tailored polynuclear complexes. Part 2.22
Pettinari, Claudio; Marchetti, Fabio; Pettinari, Riccardo; Cingolani, Augusto; Drozdov, Andrei; Troyanov, Sergei; Pettinari Claudio; Dipartimento di Scienze Chimiche, Università degli Studi; Marchetti Fabio; Dipartimento di Scienze Chimiche, Università degli Studi; Pettinari Riccardo; Dipartimento di Scienze Chimiche, Università degli Studi; Cingolani Augusto; Dipartimento di Scienze Chimiche, Università degli Studi; Drozdov Andrei; Moscow State University, Chemistry Department; Troyanov Sergei; Moscow State University, Chemistry Department
Журнал:
Journal of the Chemical Society, Dalton Transactions
Дата:
2001
Аннотация:
From the interaction of organotin(iv) halides SnR2Cl2 with 1,4-bis(5-hydroxy-1-phenyl-3-methyl-1H-pyrazol-4-yl)butane-1,4-dione (Q2QH2) in methanol in the presence of base the complexes [SnR2(Q2Q)] (1: R = isobutyl (Bu<sup>i</sup>); 2: R = n-octyl (Ot); 3: R = n-dodecyl (Do)) have been synthesised. The reaction between equimolar quantities of R2SnO and Q2QH2 in toluene yields the dinuclear derivatives [SnR2(Q2Q)]2 4 (R = Me) and 5 (R = Bu<sup>n</sup>) which have a cis-R2Sn configuration in solution whereas from the reaction of Q2QH2 with SnMe2Cl2 in CH3OH in the presence of KOH, an insoluble probably polynuclear isomeric form of 4 formed. The reaction between Q2QH2 and (R3Sn)2O produces the derivative [(SnR3)2(Q2Q)] (6: R = Bu<sup>n</sup>; 7: R = Ph). 6 reacts with water yielding the aquo complex [(SnBu<sup>n</sup>3)2(Q2Q)(H2O)] 8. The X-ray crystal structures of [SnBu<sup>n</sup>2(Q2Q)]2 5, [(SnBu<sup>n</sup>3)2(Q2Q)] 6 and [(SnPh3)2(Q2Q)] 7 have been determined. Compound 5 is a binuclear species with the tin atoms in a distorted octahedral Sn-cis-C2O4 environment (skewed trapezoidal bipyramidal) with the Câ Snâ C angles ranging from 107.28(14) to 112.4(2)°. The two different carbonyl groups coordinate the metal with different donor abilities (the Snâ O bond lengths range from 2.132(2) to 2.209(2) â «). Compounds 6 and 7 contain a dianionic ligand (Q2Q)<sup>2â </sup> bridged to two triorganotin(iv) fragments with the tin atoms in a strongly distorted trigonal bipyramidal environment. <sup>1</sup>H, <sup>13</sup>C and <sup>119</sup>Sn NMR (rt and â 55 °C) data indicate that the diorganotin(iv) derivatives 1â 5 are not fluxional in solution whereas 6â 8 slowly undergo disproportionation reaction, affording SnR4 and [SnR2(Q2Q)]2.
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