342371-07-7Relevant articles and documents
Donor-funktionalisierte Alkinyle von Titan(IV), Kupfer(I) und Silber(I); Festk?rperstrukturen von [Ti](CCCH2NMe2)2 und {[Ti](CCtBu)2}CuCCCCC2H5
Frosch,Back,Müller,K?hler,Driess,Schiemenz,Huttner,Lang
, p. 99 - 109 (2001)
The preparation of numerous donor-functionalised acetylides with Ti(IV) and/or Group II transition metals is described. The reaction of [Ti]Cl2 (1) {[Ti]=(η5-C5H4SiMe3) 2Ti} with two equivalents of LiCCR1 [2a: R1=CMe=CH2; 2b: R1=C6H4CN-4; 2c: R1=CH2NMe2; 2d: R=C5H4N-4] affords the bis(alkynyl)titanocenes [Ti](CCR1)2 [3a: R1=CMe=CH2; 3b: R1=C6H4CN-4; 3c: R1=CH2NMe2] in good yields. While by treatment of 1 with 2d in a 1:2 molar ratio only non-characterisable products are formed, the use of [Ti](Cl)(CH2SiMe3) (4) produces [Ti](CH2SiMe3)(CCC5H4N-4) (5) in excellent yields. Monomeric, donor-functionalised copper(I) acetylides of general type {[Ti](CCR1)2}CuCCR3 [R1=tBu, 7a: R3=CCCH2CH3; 7b: R3=CMe=CH2; 7c: R3=C6H4CN-4; R1=SiMe3, 7d: R3=CMe=CH2; 7e: R3=C6H4CN-4] are accessible by (i) the reaction of {[Ti](CCtBu)2}CuSC6H4CH 2NMe2-2 (6) with equimolar amounts of 2a-2c or (ii) treatment of the monomeric copper(I) methyl {[Ti](CCR1)2}CuCH3 (8a: R1=SiMe3, 8b: R1=tBu) with HCCR3 [9a: R3=CCCH2CH3, 9b: R3=CMe=CH2, 9c: R3=C6H4CN-4] in a 1:1 molar ratio. The reaction chemistry of these complexes towards selected transition metal compounds is described. The bis(alkynyl)titanocenes 3a-3c produce with MLn {10a: MLn=CuCl; 10b: MLn=CuI; 10c: MLn=[Cu(CH3CN)4][PF6]; 10d: MLn=AgBF4; 10e: MLn=Ni(CO)4} the heterobimetallic tweezer complexes {[Ti](CCR1)2}ML [R1=CMe=CH2; 11a: ML=CuCl; R1=C6H4CN-4; 11b: ML=CuCl; 11c: ML=CuI; 11d: ML=Ni(CO); R1=CH2NMe2; 11e: ML=CuPF6; 11f: ML=AgBF4]. In complexes 11a-11f an early and a late transition metal centre [e.g. Ni(0)] are linked via the corresponding R1CC ligands of the organometallic π-tweezer complexes. For complexes 11e and 11f a dynamic behaviour is observed in solution. The solid state structures of 3c and 7a are reported. Both compounds crystallise in the triclinic space group P1?. They exhibit features that are characteristic for this class of complexes: (i) a tetrahedral environment around the Ti(IV) of 3c and 7a, (ii) a lengthening of the CC triple bonds upon η2-coordination to the transition metal complex fragment CuCCCCC2H5, (iii) a trans-deformation of the Ti-CC-tBu unit, and (iv) a reduction of the bite angle CCC-Ti-CCC for 7a.
