Structural and nonlinear optical properties of aligned heterotrinuclear [Ru(II)-(Spacer)-M(II)-(Spacer)-Ru(II)] complexes (M = Pd, Pt; spacer = 4-ethynylpyridine)

Qingchun Ge; Gulliver T Dalton; Mark G Humphrey; Marek Samoc; T S Andy Hor

doi:10.1002/asia.200900065

Structural and nonlinear optical properties of aligned heterotrinuclear [Ru(II)-(Spacer)-M(II)-(Spacer)-Ru(II)] complexes (M = Pd, Pt; spacer = 4-ethynylpyridine)

Chem Asian J. 2009 Jun 2;4(6):998-1005. doi: 10.1002/asia.200900065.

Authors

Qingchun Ge¹, Gulliver T Dalton², Mark G Humphrey², Marek Samoc³, T S Andy Hor¹

Affiliations

¹ Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore), Fax: (+65) 6873-1324.
² Research School of Chemistry, Australian National University, Canberra, ACT 0200 (Australia), Tel: (+02) 6125-2927.
³ Institute of Physical and Theoretical Chemistry, Wroclaw University of Technology, 50379 Wroclaw (Poland).

PMID: 19434645
DOI: 10.1002/asia.200900065

Abstract

Lewis addition between the metalloligand [RuCp(C[triple bond]Cpy-4)(dppf)] (1) (dppf = (C(5)H(4)PPh(2))(2)Fe) and MCl(2)(CH(3)CN)(2) gives [RuCp(C[triple bond]Cpy-4)(dppf)](2)[MCl(2)] (M = Pd (2) and Pt (3)), all of which have been spectroscopically and crystallographically characterized. The mixed-metal adducts show the d(6)-d(8)-d(6) metal alignment maintained by the trans disposition of the directionally rigid 4-ethynylpyridine at the centrosymmetric square-planar metal center. Electrochemical studies of these and the related known complexes trans-[RuCl(C[triple bond]Cpy-4)(dppm)(2)] (4) and [trans-RuCl(C[triple bond]Cpy-4)(dppm)(2)](2)[MCl(2)] (dppm = Ph(2)PCH(2)PPh(2)) (M = Pd (5) and Pt (6)) suggest that the spacer-linked heterotrinuclear network is able to stabilize the oxidized Ru(III) better than the metalloligand precursor. Cubic nonlinear optical responses are also generally higher for the heterometallic complexes. The gamma(real) value of the PdRu(2) dppm complex 5 is among the largest for linear organometallic complexes.