Résumé
The homo- and heterodinuclear complexes XM(mu-dppm)(2)-M'X (M = M' Pd, X = Cl 1a; M = M' = Pd, X = I 1b; M = Pd, M' = Pt, X Cl 2a; M = Pd, M'= Pt, X = I 2b; M = M' = Pt, X = Cl 3a; M = M' = Pt, X = I 3b) react with the diisocyanide ligand 1,2-bis(2-isocyanophenoxy)ethane (diNC) or the more soluble 1,2-bis (2-isocyano-4-tert-butylphenoxy)ethane (tBudiNC) in a 1:1 ratio to provide the thermally stable polymeric materials 4-9 {[XM(mu-dppm)(2)M'(mu-CN-C6H3R-2-OCH2-CH2O-2-C6H3R-NC)]X}(n), (M = M' = Pd, R = H, X = Cl 4a, I 4b; R = tBu, X = Cl 7; M = M' = Pt, R = H, X = C1 5a, I 5b; R = tBu, X = Cl 8; M = Pd, M, = Pt, R = H, X = Cl 6a, I 6b; R = tBu, X = C1 9). These A-frame-containing materials have been characterized in solution or in the solid state by P-31 NMR (MAS) spectroscopy, elemental analysis, MALDI-TOF, DSC, TGA, IR and T-1/NOE [P-31 NMR spin-lattice relaxation Lime and nuclear Overhauser enhancement constant (NOE) measurements]. The IR, Raman [v(CN) bridging vs. terminal] and NMR spectroscopic data reveal the presence of an A-frame structure for these new materials. Evidence of an oligomer (including at least two units, determined by T-1/NOE experiments) - polymer equilibrium in solution was obtained at room temperature. These polymers are luminescent (phosphorescence) at 77 K in solution and in the solid state, exhibiting broad emission bands in the 500-800 nm range. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)