Inorganic Chemistry, Vol.43, No.9, 2906-2913, 2004
Metallic macrocycle with a 1,3-alternate calix[4]arene phosphorus ligand
The preparation of an 1,3-alternate calix[4]arene phosphorus ligand, 25,27-bis(2-(diphenylphosphino)ethoxy)-26,28-bis(1-propyloxy)calix[4]are ne (3), is presented. Ligand 3 is obtained in three steps in 64% overall yield. Reaction of 3 with [Rh(cot)(2)]BF4 produced the encapsulated rhodium complex [Rh{ (P,P)-diphen-calix[4]arene }]BF4 (4). As revealed by a single-crystal X-ray diffraction study, the rhodium center has a bent coordination environment with a P-Rh-P angle of 135.66(3)degrees. Palladation of 3 employing [Pd(MeCN)(4)](BF4)(2) yielded the chelate palladium complex 7 in which the palladium center has a slightly bent configuration. Treatment of the ligand with Pd(cod)Cl-2 and [Pd(eta(3)-C4H7)(THF)(2)]BF4 leads to the isolation of the monometallic complex. Full characterization includes X-ray structural studies of compounds 3, 4, and 6.