Studies on two interesting microporous polymeric clusters {[Et4N]2[MS4Cu4(CN)4]}n (Mâ =â Mo or W) with three-dimensional open frameworks: synthesis, structural characterization, strong optical non-linearities and large optical limiting properties
Zhang, Chi; Song, Yinglin; Xu, Yan; Fun, Hoongkun; Fang, Guangyu; Wang, Yuxiao; Xin, Xinquan; Zhang Chi; State Key Laboratory of Applied Optics, Department of Physics, Harbin Institute of Technology; State Key Laboratory of Coordination Chemistry, Department of Chemistry, Nanjing University; Song Yinglin; State Key Laboratory of Applied Optics, Department of Physics, Harbin Institute of Technology; Xu Yan; State Key Laboratory of Coordination Chemistry, Department of Chemistry, Nanjing University; Fun Hoongkun; X-Ray Crystallography Unit, School of Physics, Universiti Sains Malaysia; Fang Guangyu; State Key Laboratory of Applied Optics, Department of Physics, Harbin Institute of Technology; Wang Yuxiao; State Key Laboratory of Applied Optics, Department of Physics, Harbin Institute of Technology; Xin Xinquan; State Key Laboratory of Coordination Chemistry, Department of Chemistry, Nanjing University
Журнал:
Dalton Transactions
Дата:
2000
Аннотация:
Reactions combining stoichiometric amounts of (Et4N)2MS4 (Mâ =â Mo or W) and CuCN (1â ¶4) in pyridine afforded interesting three-dimensional cluster polymers with open frameworks {[Et4N]2[MS4Cu4(CN)4]}n (Mâ =â Mo 1 or W 2). Crystal structure determination shows that the anionic MS4Cu4 units bridged by cyanide produce three-dimensional channels running down the crystallographic a axis. An alternative way to view this framework is in terms of the diamond structure, where C has alternately been replaced by a MS4Cu4 aggregate and Câ C by two parallel cyanide bridging ligands. In these intersecting channels the shortest distances between Cu atoms along the b and c axes are 15.22 and 8.11 à respectively. Non-linear optical properties of the two clusters were investigated first with an 8 ns pulsed laser at 532 nm. These two clusters exhibit large optical limiting performance with limiting threshold values of 0.28 for 1, 0.15 J cm<sup>â 2</sup> for 2 respectively. Both compounds show strong third-order NLO absorption effects (α2 1.5â à â 10<sup>â 9</sup> 1, 1.6â à â 10<sup>â 9</sup> m W<sup>â 1</sup> 2) and self-focusing performance (n2 1.84â à â 10<sup>â 16</sup> 1, 1.22â à â 10<sup>â 16</sup> m<sup>2</sup> W<sup>â 1</sup> 2) in 3.64â à 10<sup>â 5</sup> 1 and 2.93â à 10<sup>â 5</sup> mol dm<sup>â 3</sup> 2 DMF solution separately. The corresponding effective NLO susceptibilities Ï <sup>(3)</sup> are 4.58â à â 10<sup>â 9</sup> 1 and 5.12â à â 10<sup>â 9</sup> esu 2 while the corresponding hyperpolarizabilities (γ(1)â =â 1.15â à â 10<sup>â 29</sup> and γ(2)â =â 1.26â à â 10<sup>â 29</sup> esu) are also reported.
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