Abstract

The reaction of [Re-2(CO)(8)(MeCN)(2)] with cyanoethylphosphines affords mono- and disubstituted compounds where the phosphine ligand is kappa(1)(P)-coordinated. When diallylphosphines are used as ligands, the mu:kappa(3)(P, C, C)-coordination through the phosphorus atom and an allyl fragment is observed. The hemilabile behavior of the diallyl(p-methoxyphenyl) phosphine ligand was confirmed via the cleavage of the allyl p-coordination when [Re-2(CO)(8){mu:kappa(3)(P,C,C)-p-MeOC6H4P(CH2CH=CH2)(2)}](6) reacts with nucleophiles, such as CO and PPh3. In contrast, the compound [Re-2(CO)(8){mu:kappa(3)(P, C, C)-(Pr2NP)-Pr-i(CH2CH=CH2)(2)}] (4) does not react in the presence of nucleophiles, suggesting that the metal-allyl p-bonding interaction is stronger for diallyldiisopropylaminophosphine than diallyl(p-methoxyphenyl) phosphine ligand. Furthermore, photolysis of [Re-2(CO)(9){kappa(1)(P)-p-MeOC6H4P(CH2CH=CH2)(2)}] (5) and diax-[Re-2(CO)(8)(PPh3) {kappa(1)(P)-p-MeOC6H4P(CH2CH=CH2)(2)}] (8) in dichloromethane at room temperature undergoes to rhenium- rhenium bond cleavage to give mononuclear derivatives. (C) 2015 Elsevier B.V. All rights reserved.