Synthesis, characterization and reactivity of dinuclear rhenium complexes containing hemilabile phosphines as ligands: X-ray structures of diax-[Re2(CO)8{κ1(P)-Ph2P(CH2)2CN}2], [Re2(CO)8{μ:κ3(P,C,C)-iPr2NP(CH2CHCH2)2}] and diax-[Re2(CO)8(PPh3){κ1(P)-p-MeOC6H4P(CH2CHCH2)2}]
作者:Deisy Peña、Yomaira Otero、Alejandro Arce、Juan M. García、David S. Coll、Edgar Ocando-Mavarez、Rubén Machado、Teresa González
DOI:10.1016/j.ica.2015.10.013
日期:2016.1
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.