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Titolo:
TRANSITION-METAL DIAZOALKANE COMPLEXES - SYNTHESIS, STRUCTURE, AND PHOTOCHEMISTRY OF RH[C(N-2)SIME(3)](PET(3))
Autore:
DEYDIER E; MENU MJ; DARTIGUENAVE M; DARTIGUENAVE Y; SIMARD M; BEAUCHAMP AL; BREWER JC; GRAY HB;
Indirizzi:
UNIV TOULOUSE 3,CHIM INORGAN LAB,118 ROUTE NARBONNE F-31062 TOULOUSE FRANCE UNIV TOULOUSE 3,CHIM INORGAN LAB F-31062 TOULOUSE FRANCE UNIV MONTREAL,DEPT CHIM MONTREAL PQ H3C 3J7 CANADA CALTECH,DIV CHEM & CHEM ENGN PASADENA CA 91125
Titolo Testata:
Organometallics
fascicolo: 4, volume: 15, anno: 1996,
pagine: 1166 - 1175
SICI:
0276-7333(1996)15:4<1166:TDC-SS>2.0.ZU;2-C
Fonte:
ISI
Lingua:
ENG
Soggetto:
RAY CRYSTAL-STRUCTURES; X-RAY; METHYLENE COMPLEXES; PHOSPHINE COMPLEXES; CARBYNE COMPLEXES; NUCLEOPHILIC-ADDITION; KETENIMINE COMPLEXES; MOLECULAR-STRUCTURE; FLASH-PHOTOLYSIS; CARBENE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
91
Recensione:
Indirizzi per estratti:
Citazione:
E. Deydier et al., "TRANSITION-METAL DIAZOALKANE COMPLEXES - SYNTHESIS, STRUCTURE, AND PHOTOCHEMISTRY OF RH[C(N-2)SIME(3)](PET(3))", Organometallics, 15(4), 1996, pp. 1166-1175

Abstract

Reaction of RhCl(PR(3))(n) (R = Me (n = 4), Et (n = 3)) and RhCl(CO)(PEt(3))(2) with (trimethylsilyl)diazomethyl lithium at -78 degrees C in ether yields the three complexes Rh[C(N-2)- SiMe(3)](PEt(3))(3) (1),Rh[C(N-2)SiMe(3)](PMe(3))(4) (2), and Rh[C(N-2)SiMe(3)](CO)(PEt(3))(2) (3). 2 could not he isolated as a solid at room temperature but 1 was precipitated as red crystals that were stable enough to he handled under argon. X-ray ray work on 1 reveals a tetrahedrally distorted square-planar geometry with the planar (trimethylsilyl)diazomethyl ligand roughly perpendicular to the P3RhC coordination plane. This distortionmakes the PEt(3) ligands nonequivalent in the crystal and produces anABB'X pattern in the solid-state P-31 NMR spectrum. Photolysis of Rh[C(N-2)SiMe(3)](PEt(3))(3) leads quantitatively to the dimer [Rh-{C(SiMe(3))(2)](2) (4). The presence of the two ylide bridges and terminal phosphines is deduced from the COSY P-31-P-31 NMR spectrum. This photochemical reactivity suggests that the transient carbene (PEt(3))(3)RhC(SiMe(3)) is electrophilic, which is typical of a singlet carbene. We believe the singlet state is stabilized by the presence of the electron-rich low-spin Rh(PEt(3))(3) fragment. Reaction with (n)BuNC and (t)BuNC leads to stereo- and regioselective formation of a triazole that issigma bonded to the rhodium center. The X-ray structure of the (t)BuNC derivative Rh[CC(SiMe(3))N(2)N(t)Bu]((t)BuNC)(2)(PEt(3)) (5) shows adistorted square-planar geometry around Rh with the planar triazolatoligand roughly orthogonal to this plane. The probable reaction mechanism involves addition and substitution reactions of isocyanides at Rh followed by insertion into the Rh-C bond.

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Documento generato il 11/07/20 alle ore 21:11:38