| 研究実績の概要 |
The interplay of aromaticity and antiaromaticity of conjugated π systems is a crucial design strategy for tuning electronic states and properties of molecules. This project developed 3 ligand systems for transition metals, whose structure permit potential orbital interactions between metal d orbitals and ligand π orbitals. We hypothesized that by changing the number of electrons in the M-L system through redox reactions, their electronic states and electronic properties can be tuned. Using this strategy, we were able to synthesis and characterize an anionic gold complexes bearing a 4π B, N-heterocyclic Carbene (BNC). The expected antiaromaticity and the inclusion of boron atoms in BNC results in its highly π-accepting and σ-donating abilities which are ideal to stabilize the unusual oxidation state. As a comparison, a π-donating B,N-containing heterocyclic Phosphide (BNP, 6π) ligand was synthesized. Its complexation on Au(I) will allowed a structural comparison to BNC-Au(I) complexes, which revealed both terminal and bridging binding mode of the phosphine ligand. Its redox behavior is under investigation. In addition, a CCC-type pincer based on a dipyridal-annulated N-heterocyclic carbene was also developed. It complexes to a Ir(I) precursor to form a homoleptic octahedral Ir(III) bispincer metallacycle through a series of facile deprotonation/C-H activation. A step-wise 4e oxidation allowed isolation of a racemic mixture of a chiral tricationic Ir(III) complex. Experimental data and computational analysis of this complex suggested a triplet ground state.
|
