Dias H V Rasika, Diyabalanage Himashinie V K, Eldabaja Maha G, Elbjeirami Oussama, Rawashdeh-Omary Manal A, Omary Mohammad A
Department of Chemistry and Biochemistry, The University of Texas at Arlington, 76019, USA.
J Am Chem Soc. 2005 May 25;127(20):7489-501. doi: 10.1021/ja0427146.
Synthetic details, solid-state structures, and photophysical properties of a group of trimeric copper(I) complexes containing pyrazolate ligands are described. The reaction of copper(I) oxide and the fluorinated pyrazoles [3-(CF(3))Pz]H, [3-(CF(3)),5-(Me)Pz]H, and [3-(CF(3)),5-(Ph)Pz]H leads to the corresponding trinuclear copper(I) pyrazolates, {[3-(CF(3))Pz]Cu}(3), {[3-(CF(3)),5-(Me)Pz]Cu}(3), and {[3-(CF(3)),5-(Ph)Pz]Cu}(3), respectively, in high yield. The {[3,5-(i-Pr)(2)Pz]Cu}(3) compound was obtained by a reaction between [Cu(CH(3)CN)(4)][BF(4)], [3,5-(i-Pr)(2)Pz]H, and NEt(3). These compounds as well as {[3,5-(Me)(2)Pz]Cu}(3) and {[3,5-(CF(3))(2)Pz]Cu}(3) adopt trimeric structures with nine-membered Cu(3)N(6) metallacycles. There are varying degrees and types of intertrimer Cu...Cu interactions. These contacts give rise to zigzag chains in the fluorinated complexes, {[3-(CF(3))Pz]Cu}(3), {[3-(CF(3)),5-(Me)Pz]Cu}(3), {[3-(CF(3)),5-(Ph)Pz]Cu}(3), and {[3,5-(CF(3))(2)Pz]Cu}(3), whereas the nonfluorinated complexes, {[3,5-(Me)(2)Pz]Cu}(3) and {[3,5-(i-Pr)(2)Pz]Cu}(3) form dimers of trimers. Out of all the compounds examined in this study, {[3-(CF(3)),5-(Ph)Pz]Cu}(3) has the longest (3.848 Angstroms) and {[3,5-(Me)(2)Pz]Cu}(3) has the shortest (2.946 Angstroms) next-neighbor intertrimer Cu...Cu distance. The Cu...Cu separations within the trimer units do not vary significantly (typically 3.20-3.26 Angstroms). All of these trinuclear copper(I) pyrazolates show bright luminescence upon exposure to UV radiation. The luminescence bands are hugely red-shifted from the corresponding lowest-energy excitations, rather broad, and unstructured even at low temperatures, suggesting metal-centered emissions owing to intertrimer Cu...Cu interactions that are strengthened in the phosphorescent state. The {[3-(CF(3)),5-(Ph)Pz]Cu}(3) compound exhibits an additional highly structured phosphorescence with a vibronic structure corresponding to the pyrazolyl (Pz) ring. The luminescence properties of solids and solutions of the trimeric compounds in this study show fascinating trends with dramatic sensitivities to temperature, solvent, concentration, and excitation wavelengths.
描述了一组含吡唑酸盐配体的三聚体铜（I）配合物的合成细节、固态结构和光物理性质。氧化铜与氟化吡唑[3-(CF(3))Pz]H、[3-(CF(3)),5-(Me)Pz]H和[3-(CF(3)),5-(Ph)Pz]H反应，分别以高产率生成相应的三核铜（I）吡唑酸盐{[3-(CF(3))Pz]Cu}₃、{[3-(CF(3)),5-(Me)Pz]Cu}₃和{[3-(CF(3)),5-(Ph)Pz]Cu}₃。{[3,5-(i-Pr)₂Pz]Cu}₃化合物是通过[Cu(CH₃CN)₄][BF₄]、[3,5-(i-Pr)₂Pz]H和NEt₃之间的反应得到的。这些化合物以及{[3,5-(Me)₂Pz]Cu}₃和{[3,5-(CF(3))₂Pz]Cu}₃采用具有九元Cu₃N₆金属环的三聚体结构。三聚体间存在不同程度和类型的Cu…Cu相互作用。这些接触在氟化配合物{[3-(CF(3))Pz]Cu}₃、{[3-(CF(3)),5-(Me)Pz]Cu}₃、{[3-(CF(3)),5-(Ph)Pz]Cu}₃和{[3,5-(CF(3))₂Pz]Cu}₃中形成锯齿链，而非氟化配合物{[3,5-(Me)₂Pz]Cu}₃和{[3,5-(i-Pr)₂Pz]Cu}₃形成三聚体二聚体。在本研究中考察的所有化合物中，{[3-(CF(3)),5-(Ph)Pz]Cu}₃具有最长的（3.848埃）且{[3,5-(Me)₂Pz]Cu}₃具有最短的（2.946埃）三聚体间最近邻Cu…Cu距离。三聚体单元内的Cu…Cu间距变化不显著（通常为3.20 - 3.26埃）。所有这些三核铜（I）吡唑酸盐在紫外辐射照射下均发出明亮的光。发光带相对于相应的最低能量激发有极大的红移，相当宽，甚至在低温下也无结构，表明由于三聚体间Cu…Cu相互作用导致以金属为中心的发射，这种相互作用在磷光态下增强。{[3-(CF(3)),5-(Ph)Pz]Cu}₃化合物表现出额外的高度结构化磷光，具有与吡唑基（Pz）环对应的振动结构。本研究中三聚体化合物的固体和溶液的发光性质呈现出迷人的趋势，对温度、溶剂、浓度和激发波长具有显著的敏感性。
