Osmium (II) complexes based based upon the 2-[(diphenylphosphanyl)-methyl]-pyridine ligand

INOR 44

Gregory D Phelan, gphelan@u.washington.edu, Jason B. Benedict, jxenon54@u.washington.edu, Werner Kaminsky, kaminsky@wintensor.com, and Brenden Carlson. Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195
We report new osmium complexes based upon the 2-[(diphenylphosphanyl)-methyl]-pyridine ligand. Hexafluorophosphate salts of bis(3,4,7,8-tetramethyl-1,10-phenantholine)( 2-[(diphenylphosphanyl)-methyl]-pyridine)osmium(II) (1), and bis(2-[(diphenylphosphanyl)-methyl]-pyridine)(4,7-diphenyl-1,10-phenanthroline)osmium(II) (2) have been synthesized and x-ray structures obtained. Indexing and unit cell refinement of 1 indicated a monoclinic P lattice. The space group was found to be P1 (No.2). Indexing and unit cell refinement of 2 indicated a monoclinic P lattice. The space group was found to be P 21/c. The P-Os bond length in 1 was observed to be 226.9 pm and 233.56 for 2. Complex 2 was found to be as the trans isomer where P was trans to P in the z direction and all 4 N were transto N in the xy plane of the complex. This isomer of 2 may have been preferred over the cis isomer due to crowding effects of the phenyl groups on the phosphorous. Both 1 and 2 were found to have the same emission at 640 nm despite the differences in structure.