306763-46-2Relevant academic research and scientific papers
Organometallic complexes for nonlinear optics: Part 19. Syntheses and molecular quadratic hyperpolarizabilities of indoanilino-alkynyl-ruthenium complexes
McDonagh, Andrew M.,Cifuentes, Marie P.,Lucas, Nigel T.,Humphrey, Mark G.,Houbrechts, Stephan,Persoons, André
, p. 193 - 201 (2007/10/03)
The terminal alkyne 4-HCCC6H4N=CCH=CtBuC(O)CtBu=CH (1) and ruthenium complex derivatives trans-[Ru(CC-4-C6H4N=CCH=CtBuC(O)C tBu=CH}Cl(dppm)2] (2) and [Ru{CC-4-C6H4N=CCH=CtBuC(O)C tBu=CH}(PPh3)2(η-C5H 5)] (3) have been synthesized. An X-ray structural study of 3 reveals the expected equivalent C-C bond lengths of the phenyl and alternating C-C and C=C bond lengths of the quinonal ring in the indoanilino-alkynyl ligand; there is a dihedral angle of 47.59° between the phenyl and quinonal rings, probably a result of ortho-hydrogen repulsion. Metal-centred oxidation potentials of 2 and 3 are similar to those of 'extended chain' 4-nitroaryl-alkynyl complex analogues. Irreversible quinonal ring-centred reductions occur at significantly more negative potentials than the quasi-reversible reductions in their nitro-containing analogues. Quadratic optical nonlinearities by hyper-Rayleigh scattering at 1064 nm for 2 (417×10-30 esu) and 3 (658×10-30 esu) are both large, but resonance enhanced. Two-level-corrected nonlinearities for these complexes (124×10-30, 159×10-30 esu, respectively) are also large, despite the presence of electron-donating tert-butyl groups reducing the efficiency of the (formally) electron-accepting quinonal ring in these donor-bridge-acceptor complexes.
