Syntheses and quadratic hyperpolarizabilities of some (pyridylalkynyl)metal complexes: crystal structures of [Ni{2-(CC)C5H3NNO2-5}(PPh3)(η-C5H5)], [Au{2-(CC)C5H3NNO2-5}(PPh3)] and [Au{2-(CC)C5H4N}(PPh3)] ‡
作者:Raina H. Naulty、Marie P. Cifuentes、Mark G. Humphrey、Stephan Houbrechts、Carlo Boutton、André Persoons、Graham A. Heath、David C. R. Hockless、Barry Luther-Davies、Marek Samoc
DOI:10.1039/a702249b
日期:——
The complexes [Ru2-(CC)C5H3NR-5}(PPh3)2(η-C5H5)] (R = NO2 1 or H 2), [Ni2-(CC)C5H3NR-5}(PPh3)(η-C5H5)] (R = NO2 3 or H 4) and [Au2-(CC)C5H3NR-5}L] (L = PPh3, R = NO2 5 or H 6; L = PMe3, R = NO2 7) have been synthesized and 3, 5 and 6 structurally characterized; no significant increase in quinoidal vinylidene contribution to the acetylide ground-state structure is apparent on progression from structurally characterized phenylacetylide complexes to the new pyridylacetylide complexes, or upon replacement of 5-H by 5-NO2 in progressing from 6 to 5. The molecular quadratic optical non-linearities of 1â7 have been determined by hyper-Rayleigh scattering (HRS). The HRS measurements at 1064 nm are consistent with an increase in β upon replacement of phenyl by an N-heterocyclic ring (replacing a nitrophenylacetylide by a nitropyridylacetylide ligand) for the ruthenium and gold systems, but with no change for the nickel complexes, and with an increase in non-linearity upon replacement of PMe3 by PPh3 in progressing from 7 to 5. The bulk second-order susceptibilities of the series have been determined by Kurtz powder measurements at 1064 nm, with the only significant response (about eight times that of urea) being that of 3; this complex was the only one of the three structurally characterized to pack non-centrosymmetrically in the crystal lattice. Electrochemical data for 1â4 have been obtained; comparison to analogous nitrophenylacetlylide complexes reveals that replacing nitrophenylacetylide by nitropyridylacetylide leads to a significant increase in MII/III oxidation potential for the ruthenium complexes, but to no change for the nickel examples. The parameter E°MII/III â E°NO2/NO2â was evaluated for 1â4, results for M = Ru vs. Ni being consistent with experimentally determined non-linearities, i.e. smaller ÎE° and larger non-linearities for ruthenium vs. nickel.
复合物 [Ru2-(CC)C5H3NR-5}(PPh3)2(η-C5H5)] (R = NO2 1 或 H 2)、[Ni2-(CC)C5H3NR-5}(PPh3)(η-C5H5)] (R = NO2 3 或 H 4) 和 [Au2-(CC)C5H3NR-5}L] (L = PPh3, R = NO2 5 或 H 6; L = PMe3, R = NO2 7) 已被合成并结构表征 3、5 和 6;从结构表征的苯乙炔基复合物到新的吡啶乙炔基复合物,或从 6 到 5 替换 5-H 为 5-NO2 的过程中,乙炔基的醌式乙烯基贡献对乙炔基基态结构的显著增加并不明显。分子二阶非线性光学性质已通过超雷利散射(HRS)测定。HRS 测量在 1064 nm 处与通过用 N-杂环替代苯基 (用硝基吡啶乙炔基取代硝基苯乙炔基配体) 在钌和金系统中增加 β 一致,但对镍复合物没有变化,并且在从 7 到 5 的过程中用 PPh3 替代 PMe3 时非线性增加。通过 Kurtz 粉末测量在 1064 nm 处确定了系列的有效二阶极化率,唯一显著的响应 (约为尿素的八倍) 来自 3;这种复合物是三个结构表征中唯一一个在晶格中非中心对称排列的。获得了 1-4 的电化学数据; 与类似的硝基苯乙炔基复合物比较,用硝基吡啶乙炔基替代硝基苯乙炔基会导致钌复合物的 MII/III 氧化电位显著增加,但对镍复合物没有变化。对 1-4 评估了参数 E°MII/III - E°NO2/NO2,结果 M = Ru 和 Ni 与实验确定的非线性一致,即较小的 ÎE° 和较大的非线性对于钌比镍。