Cyclopentadienyl and Other Complexes

3 Cyclopentadienyl and Other Complexes.- Chiral complexes CpMo(CO)2[N(R )=C(R)C(0)0], containing N,0-chelating 2-imino-carboxylate groups, have been synthesised from [CpMo(CO) Cll, 

CH2C02Et, or (S)-CHMePh]. Irradiation of [(h-MeCgH )Mo(CO)3]2 in the presence ofPCOMe) effects both substitution and disproportionation. The products are 

The importance of 19-electron intermediates in such disproportionations is supported by the observation that [(rrMeC3H )Mo(CO)2(trlphos)containing 

PhP(H)(OCH2CH2)2N results in the formation of [CP2MO2(CO)3L], which retains the metal-metal triple bond, and [CP2MO2(CO) L] 

X = Cl or NMe,), undergo elimination of HX to afford the novel species [CpM(CO)2(POCH CH O)] containing M-P double bonds. The phosphavinylidene complex CpMo(CO)2lP C(SiMe2)2 has a two-coordinate phosphorus atom engaged in multiple bonding to both carbon and molybdenum.  

2 Cyclopentadienyl and Other Complexes.— The three products [(n-C5H4Me)Mn(C0)2(NC5H4CN)l, ((n-CgH4Me)Mn(CO)2(NCC H N)] and [ (Ti-CgH4Me)Mn(CO)2 2 tyNCCgH N)), separable by low temperature chromatography, result from the reaction of 

However, Kaim et using e.s.r. evidence formulate such complexes 

The very unstable sulphur monoxide, generated by thermolysis 

Thermolysis of the rhenacyclopentane [CpRe(CO)2 (CH2)2CH2 ) in the presence of PR (R = Me or Ph) affords methylcyclopropane and [CpRe(CO)2(PRj)]f the reactions being first-order in rhenacyclopentane and independent of phosphine concentration. It is 5 3 

The pyrrolyl ring nitrogen of the product possesses considerable 

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