p-tert-Butylcalix[4]arene Tetrakis(diphenylphosphinite) and Tetrakis(dimethylphosphinite) Acting as Phosphorus Binding Surfaces for Monometallic and Homo- and Heterodimetallic Fragments.

摘要: p-tert-Butylcalix[4]arene tetrakis(diphenylphosphinite), calix[4]-(PPh(2))(4) (1), and tetrakis(dimethylphosphinite), calix[4]-(PMe(2))(4) (2), provide a phosphorus surface consisting of four coplanar trivalent atoms for binding two metal ions into close geometrical proximity. Homodimetallic complexes have been obtained in the reaction 1 with [(COD)MCl(2)] [COD = cycloocta-1,5-diene], namely, [{calix[4]-(PPh(2))(4)}(MCl(2))(2)] [M Pd (3), Pt (4)]. Characterizations by (1)H (31)P NMR were particularly informative showed how bridging methylene calix[4]arene skeleton may function as spectroscopic probe. A dimeric complex was reacting [Rh(CO)(2)Cl](2) to give [{calix[4]-(PPh(2))(4)}{Rh(CO)Cl}(2)] (5). Reaction excess NiCl(2) gave exclusively monometallic complex, [{calix[4]-(PPh(2))(4)}NiCl(2)] (6), regardless stoichiometry used. The analogous (7) undergoes ligand disproportionation reaction, while corresponding analogue does not exist under same conditions. Complex 6 represents good entry dinuclear heterodimetallic complexes. In fact, its [(NBD)Mo(CO)(4)] [NBD norbornadiene] led [{calix[4]-(PPh(2))(4)}NiCl(2){Mo(CO)(4)}] (8). use more basic less sterically demanding 2 synthesis homonuclear bimetallic [{calix[4]-(PMe(2))(4)}(MCl(2))(2)] Ni (9), (10), (11)].