Synthese und reaktionsverhalten chloro-funktionalisierter alkinyl-phosphane; stufenweise darstellung von σ3, λ4-phosphandiyl-komplexen mit einer phosphor-cobalt-bzw. Phosphor-molybdän-doppelbindung

Abstract

The reaction of (R)PCl 2 (R = 2,4,6- t Bu 3C 6H 2O) ( 1) with LiCCLi ( 2) affords in high yield (R)(Cl)PCCP(Cl)(R) ( 3). The compounds (R)(Cl)PCCP(Cl)(R) ( 3) and (R)(PhCC)P(Cl) ( 4) react with equimolar amounts of Co 2(CO) 8 ( 5) to yield the complexes (R)(Cl)P[( η 2CC)Co 2(CO) 6]P(Cl)(R) ( 6) (reaction of 3 and 5) or (R)[ η 2CCPh)Co 2(CO) 6]P(Cl) ( 7) and R)[( η 2CCPh(Co) 2(CO) 6]PCo(CO) 3 ( 8) (reaction of 4 with 5). The C 2 unit of the alkynyl building blocks in compounds 6–8 is η 2-coordinated to a Co 2(CO) 6 fragment, forming a carbon-cobalt tetrahedrane moiety. 7 yields with further Co 2(CO) 8 ( 5) by reductive dehalogenation the σ 3, λ 4-phosphanediyl complex (R)[( η 2CCPh)Co 2(CO) 6]PCo(CO) 3 ( 8). In 8 the bulky organometallic building block ( η 2CCPh)Co 2(CO) 6 sterically protects the otherwise reactive phosphorus-cobalt double bond. 8 can also be synthesized by the reaction of 7 with Na[Co(CO) 4] ( 9). When Na[MoCp(CO) 3] ( 10) is used, the compound (R)[( η 2CCPh)Co 2(CO) 6]PMoCp(CO) 2 ( 11) is formed. However, 6 shows no reaction with 5, 9 or 10. All synthesized compounds have been characterized by analytical and spectroscopic data (IR, 1H, 13C, 31P NMR, MS).