Organometallic complexes for nonlinear optics. 14. Syntheses and second-order nonlinear optical properties of ruthenium, nickel and gold σ-acetylides of 1,3,5-triethynylbenzene: X-ray crystal structures of 1-(HC ≡ C)-3,5-C₆H₃(trans-C ≡ CRuCl(dppm)₂)₂ and 1,3,5-C₆H₃(C ≡ CAu(PPh₃))₃

Abstract

The complexes 1-(HC ≡ C)-3,5-C6H3[M]2 ([M] = trans-C ≡ CRuCl(dppm)2 (1), C ≡ CNi(PPh3)(η5-C5H5) (2)) and 1,3,5-C6H3(C ≡ CAu(PPh3))3 (3) have been prepared by extensions of well-established σ-acetylide synthetic methodologies, and 1 and 3 have been structurally characterized. Steric restrictions preclude coordination of three trans-RuCl(dppm)2 or Ni(PPh3)(η5-C5H5) moieties about the central 1,3,5-triethynylbenzene unit, a problem which the smaller Au(PPh3) group does not experience. The quadratic optical nonlinearities at 1.06 μm have been investigated by hyper-Rayleigh scattering with the C2h symmetry complexes 1 and 2 having significantly larger βHRS than their monometallic [M]C ≡ CPh ([M] = trans-RuCl(dppm)2 (4) and Ni(PPh3)(η5-C5H5) (5)) counterparts. The D3h symmetry octopolar complex 3 has a similar nonlinearity to its dipolar monometallic analogue Au(C ≡ CPh)(PPh3) (6). Complexes 1, 2 and 3 have λmax similar to 4, 5 and 6 (i.e., no loss of optical transparency is observed), but have significantly larger oscillator strengths for the important optical transitions. Show more