Diazodi(4-pyridyl)methane and Diazophenyl-(4-pyridy[)methane as Photoresponsive Ligands for Metal-Carbene Hetero-Spin Systems

摘要

Diphenylcarbene with a triplet ground state has served as an important building block in the construction of molecules and molecular assemblies with high spin multiplicities. Thus the connection of n carbene units through meta-phenylene, 1,3,5-benzenetriyl, and other ferromagnetic coupling units gives rise to various pohcarbenes with 5 = n ground stales: in the series the highest spin state reported so far is S = 9. Efforts to increase the number of aligned spins have, however, been hampered by the development of antiferromagnetie intra- and or interchain interactions between the carbene centers assembled in high local concentration: chemical bonds appear 10 be formed in the extreme case. Our last recourse is a strategy of assembling carbene centersin a rigid polymeric metal complex. We report here on the ligation of the pyridyl nitrogens of diazodi-(4-pyridyl (methane (1) with coordinatively doubly misaturated paramagnetic metal ions and on the photolysis of the resulting complex.