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The reaction of (R)PCl 2 (R = 2,4,6- t Bu 3 C 6 H 2 O) ( 1 ) with LiCCLi ( 2 ) affords in high yield (R)(Cl)PCCP(Cl)(R) ( 3 ). The compounds (R)(Cl)PCCP(Cl)(R) ( 3 ) and (R)(PhCC)P(Cl) ( 4 ) react with equimolar amounts of Co 2 (CO) 8 ( 5 ) to yield the complexes (R)(Cl)P[( η 2 CC)Co 2 (CO) 6 ]P(Cl)(R) ( 6 ) (reaction of 3 and 5 ) or (R)[ η 2 CCPh)Co 2 (CO) 6 ]P(Cl) ( 7 ) and R)[( η 2 CCPh(Co) 2 (CO) 6 ]PCo(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 CCPh)Co 2 (CO) 6 ]PCo(CO) 3 ( 8 ). In 8 the bulky organometallic building block ( η 2 CCPh)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 CCPh)Co 2 (CO) 6 ]PMoCp(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, 1 H, 13 C, 31 P NMR, MS). |
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