Luminescent Ag<sup>I</sup>−Cu<sup>I</sup> Heterometallic Hexa-, Octa-, and Hexadecanuclear Alkynyl Complexes
journal contribution
posted on 2004-05-31, 00:00 authored by Qiao-Hua Wei, Gang-Qiang Yin, Li-Yi Zhang, Lin-Xi Shi, Zong-Wan Mao, Zhong-Ning ChenA series of Ag<sup>I</sup>−Cu<sup>I</sup> heteronuclear alkynyl complexes were prepared by reaction of polymeric (MC⋮CC<sub>6</sub>H<sub>4</sub>R-4)<i><sub>n</sub></i> (M
= Cu<sup>I</sup> or Ag<sup>I</sup>; R = H, CH<sub>3</sub>, OCH<sub>3</sub>, NO<sub>2</sub>, COCH<sub>3</sub>) with [M‘<sub>2</sub>(<i>μ</i>-Ph<sub>2</sub>PXPPh<sub>2</sub>)<sub>2</sub>(MeCN)<sub>2</sub>](ClO<sub>4</sub>)<sub>2</sub> (M‘ = Ag<sup>I</sup> or Cu<sup>I</sup>; X =
NH or CH<sub>2</sub>). Heterohexanuclear complexes [Ag<sub>4</sub>Cu<sub>2</sub>(<i>μ</i>-Ph<sub>2</sub>PNHPPh<sub>2</sub>)<sub>4</sub>(C⋮CC<sub>6</sub>H<sub>4</sub>R-4)<sub>4</sub>](ClO<sub>4</sub>)<sub>2</sub> (R = H, <b>1</b>; CH<sub>3</sub>, <b>2</b>)
were afforded when X = NH, and heterooctanuclear complexes [Ag<sub>6</sub>Cu<sub>2</sub>(<i>μ</i>-Ph<sub>2</sub>PCH<sub>2</sub>PPh<sub>2</sub>)<sub>3</sub>(C⋮CC<sub>6</sub>H<sub>4</sub><i>R</i>-4)<sub>6</sub>(MeCN)](ClO<sub>4</sub>)<sub>2</sub> (R = H, <b>3</b>; CH<sub>3</sub>, <b>4</b>; OCH<sub>3</sub>, <b>5</b>; NO<sub>2</sub>, <b>6</b>) were isolated when X = CH<sub>2</sub>. Self-assembly reaction between
(MC⋮CC<sub>6</sub>H<sub>4</sub>COCH<sub>3</sub>-4)<i><sub>n</sub></i> and [M‘<sub>2</sub>(<i>μ</i>-Ph<sub>2</sub>PCH<sub>2</sub>PPh<sub>2</sub>)<sub>2</sub>(MeCN)<sub>2</sub>](ClO<sub>4</sub>)<sub>2</sub>, however, gave heterohexadecanuclear complex
[Ag<sub>6</sub>Cu<sub>2</sub>(<i>μ</i>-Ph<sub>2</sub>PCH<sub>2</sub>PPh<sub>2</sub>)<sub>3</sub>(C⋮CC<sub>6</sub>H<sub>4</sub>COCH<sub>3</sub>-4)<sub>6</sub>]<sub>2</sub>(ClO<sub>4</sub>)<sub>4</sub> (<b>7</b>). The heterohexanuclear complexes <b>1</b> and <b>2</b> show a
bicapped cubic skeleton (Ag<sub>4</sub>Cu<sub>2</sub>C<sub>4</sub>) consisting of four Ag<sup>I</sup> and two Cu<sup>I</sup> atoms and four acetylide C donors. The
heterooctanuclear complexes <b>3</b>−<b>6</b> exhibit a waterwheel-like structure that can be regarded as two Ag<sub>3</sub>Cu(C⋮CC<sub>6</sub>H<sub>5</sub>)<sub>3</sub> components put together by three bridging Ph<sub>2</sub>PCH<sub>2</sub>PPh<sub>2</sub> ligands. The heterohexadecanuclear complex <b>7</b>
can be viewed as a dimer of heterooctanuclear complex [Ag<sub>6</sub>Cu<sub>2</sub>(<i>μ</i>-Ph<sub>2</sub>PCH<sub>2</sub>PPh<sub>2</sub>)<sub>3</sub>(C⋮CC<sub>6</sub>H<sub>4</sub>COCH<sub>3</sub>-4)<sub>6</sub>](ClO<sub>4</sub>)<sub>2</sub>
through the silver and acetyl oxygen (Ag−O = 2.534 (4) Å) linkage between two waterwheel-like Ag<sub>6</sub>Cu<sub>2</sub> units. All
of the complexes show intense luminescence in the solid states and in fluid solutions. The microsecond scale of
lifetimes in the solid state at 298 K reveals that the emission is phosphorescent in nature. The emissive state in
compounds <b>1</b>−<b>5</b> is likely derived from a <sup>3</sup>LMCT (C⋮CC<sub>6</sub>H<sub>4</sub>R-4 → Ag<sub>4</sub>Cu<sub>2</sub> or Ag<sub>6</sub>Cu<sub>2</sub>) transition, mixed with a metal
cluster-centered (d → s) excited state. The lowest lying excited state in compounds <b>6</b> and <b>7</b> containing electron-deficient 4-nitrophenylacetylide and 4-acetylphenylacetylide, respectively, however, is likely dominated by an intraligand
<sup>3</sup>[π → π*] character.
History
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- 1. DOI - Is supplement to Luminescent AgI−CuI Heterometallic Hexa-, Octa-, and Hexadecanuclear Alkynyl Complexes
