The compound [RhCl2(η5-C5Me5) (PPh3)] reacts with Li(CH2SiMe3) to give the ortho-metallated complex [R[graphic omitted]Ph2)(CH2SiMe3)(η5-C 5Me5)] (2), and with Mg(CH2SiMe3)Cl in CH2Cl2 (molar ratio 1:1) to yield [RhCl(CH2SiMe3) (η5-C5Me5) (PPh3)], (3). Complex (3) is converted by the action of Li(CH2SiMe3) into the ortho-metallated compound (2). The reaction of [IrCl2(η5-C5Me5)-(PPh 3)] with Mg(CH2SiMe3)Cl in CH2Cl2 gives [I[graphic omitted]Ph2)(CH2SiMe3)(η5-C 5Me5)], (6), and [lrCl(Me)(η5-C5Me5)(PPh3)]. Reaction of [RhCl2(η5-C5Me5)(PPh 3)] with Mg(CH2CMe3)Cl or Li(CH2CMe3) in diethyl ether affords a mixture of [R[graphic omitted]H2)(η5 -C5Me5)(PPh3)], [R[graphic omitted]Ph2)(CH2CMe3)(η5-C 5Me5)], and [Rh(η5-C5Me5)(C2H 4)(PPh3)], while reaction in CH2Cl2 in equimolar amounts gives [RhCl(CH2CMe3)(η5-C5Me 5)(PPh3)]. Reaction of [lrCl2(η5-C5Me5) (PPh3)] with Mg(CH2CMe3)Cl gives [I[graphic omitted]Ph2)(CH2CMe3)(η5 -C5Me5)]. The X-ray crystal structure analysis of compound (6) has been carried out: a = 17.537(7), b = 11.304(4), c = 15.410(7) Å, β = 94.49(1)°, space group P21/n, Z = 4, R = 0.0361 for 4114 observed reflections. The 'piano-stool' metal co-ordination polyhedron is deformed by ortho-metallation which imposes a 67.0(2)° angle at iridium in the metallacycle, while the other angles, P-Ir-C(17) 89.0(2) and C(17)-Ir-C(36) 89.2(2)°, between the 'legs' of the 'stool' are near to 90°. The bulky C5Me5 ligand (effective cone angle 146°), in approaching the metal, produces large widenings of the other co-ordination polyhedron angles: Cp-Ir-P 137.0(3), Cp-Ir-C(36) (benzene)133.4(3)°, and Cp-Ir-C(17) (silyl)122.6(3)° (Cp = centroid of C5Me5). The ortho-metallated ring is nearly planar, (P-Ir-C) ∧ (P-C-C) 5.3(3)°, and bent by only 6.6(2)° with respect to the metal-bound benzene ring which maintains its planarity; the only deformation this ring suffers involves the endocyclic angles at the carbon bound to phosphorus which widen to 124.5(5)° and at the ortho carbons which narrow to 115.9(6) and 116.7(5)°.
|Autori:||ANDREUCCI L; DIVERSI P; INGROSSO G; LUCHERINI A; MARCHETTI F; ADOVASIO V; NARDELLI M|
|Titolo:||Neopentyl and Trimethylsilylmethyl Compounds of Rhodium(III) and Iridium(III) with ortho-Metallated Triphenylphosphine. X-Ray Crystal Structure of [Ir(C6H4PPh2)(CH2SiMe3)(eta-5-C5Me5)]|
|Anno del prodotto:||1986|
|Digital Object Identifier (DOI):||10.1039/dt9860000803|
|Appare nelle tipologie:||1.1 Articolo in rivista|