NOVEL GEOMETRIES EXHIBITED BY THREE PALLADIUM(II) MACROCYCLIC COMPLEXES - CRYSTAL AND SOLUTION STRUCTURES

摘要

The synthesis of three related macrocyclic complexes of palladium(II) is reported, together with their structural characterization by crystallography and NMR. The crystal structure of [PdL(1)](Cl)(PF6) (L(1) = 1,4,7-trithia-11-azacyclotetradecane) (P (1) over bar (No. 2), a = 10.127(2) Angstrom, b = 12.568(4) Angstrom, c = 7.141(2) Angstrom, a = 87.99(2)degrees, beta = 95.55(2)degrees, gamma = 91.02(2)degrees, Z = 2, R = 0.0422, R(W) = 0.0486) exhibits an 'endo' coordination of the metal ion. For the related pendant-arm macrocylic ligand, N-(2'-pyridylmethyl)-1,4,7-trithia-11-azacyclotetradecane (L(2)), the solid state structures of the [PdL(2)Cl](PF6) (P2(1)2(1)2(1) (NO. 19), a = 13.305(3) Angstrom, b = 12.413(4) Angstrom, c = 14.060(3) Angstrom, Z = 4, R = 0.0538, R(W) = 0.0529) and [PdL(2)](BF4)(2) . 0.5H(2)O (I2/a (No. 15) (non-standard setting of the space group C2/c), a = 19.045(8) Angstrom, b = 16.952(4) Angstrom, c = 16.635(6) Angstrom, beta = 113.47(3)degrees, Z = 8, R = 0.0532, R(W) = 0.0560) compounds exhibit a palladium ion that is 'chelated' by the macrocyclic ligand and is only partially coordinated by the macrocyclic donor set. Each of these latter complexes exhibits fluxional NMR spectra. The former complex ion undergoes a simple inner-sphere substitution while the latter exhibits more complex behaviour. [References: 48]