Reactant ratio-modulated six new copper(i)–iodide coordination complexes based on diverse [CumIm] aggregates and biimidazole linkers: syntheses, structures and temperature-dependent luminescence properties

• Published in: CrystEngComm 2013-01, Vol.15 (38), p.7792-7802
• Main Authors: Yuan, Shuai, Wang, Hua, Wang, Deng-Xu, Lu, Hai-Feng, Feng, Sheng-Yu, Sun, Di
• Format: Article
• Language: English
• Subjects: Aggregates; Diffraction; Luminescence; Ribbons; Single crystals; Stepped; Two dimensional; X-rays
• ISSN: 1466-8033; 1466-8033
• DOI: 10.1039/c3ce41021h

A total of six copper(i)-iodide coordination complexes with diverse [Cu sub(m) sub(m)] aggregates and bidentate biimidazole bridging ligands, [Cu sub(2)I sub(2)(dmimb)] sub(n)(1), [Cu sub(4)I sub(4)(dmimb)] sub(n)(2), [Cu sub(6)I sub(6)(dmimb) sub(3)] sub(n)(3)], [Cu sub(4)I sub(4)(dimb)] sub(n)(4), [Cu sub(2)I sub(2)(dimb) sub(2)] sub(n)(5), and [Cu sub(4)I sub(4)(dimb) sub(3)] sub(n)(6), (dmimb = 1,4-di(2-methyl-imidazol-1-yl)butane, dimb = 1,3-di(imidazol-1-yl)benzene), have been synthesized and structurally characterized by single-crystal X-ray diffraction analyses and further characterized by infrared spectra (IR), elemental analyses, powder X-ray diffraction (PXRD) and thermogravimetric analyses (TGA). Single-crystal X-ray diffraction analysis reveals that 1 is a double-chain based 1D ribbon incorporating a discrete [Cu sub(4)I sub(4)] stepped cubane aggregate. Complex 2 is a 2D layer based on the 1D infinite [Cu sub(6)I sub(6)] sub(n) column aggregate. Complex 3 is a triple-chain based 1D ribbon incorporating a discrete ladder-like [Cu sub(6)I sub(6)] aggregate. Interestingly, 1 and 3 are a pair of genuine supramolecular isomers controlled by the reaction ratio with an identical chemical composition. In the 2D layered structure of complex 4, the rare "S-shaped-double-bowl" Cu sub(10)I sub(10) aggregate is observed and share the Cu sub(2)I sub(2) rhomboids to form the 1D infinite [Cu sub(10)I sub(10)] sub(n) column. Complex 5 is a binuclear 18-membered metal-organic macrocycle with [CuI] monomeric units. Complex 6 is also a 2D layer constructed from a 1D infinite [Cu sub(8)I sub(8)] sub(n) aggregate which consists of a 1D infinite [Cu sub(6)I sub(6)] sub(n) column and a [Cu sub(2)I sub(2)] sub(n) ladder. In the overall view, the biimidazole linkers play an important role in the formation of diverse [Cu sub(m)I sub(m)] aggregates as well as the resulting structures and topologies. The structural changes of 1/2/3 and 4/5/6 are highly influenced due to the change of the reaction stoichiometry. For 1, 2, 5 and 6, they are non-emissive at both 298 K and 77 K, whereas 3 and 4 exhibit interesting temperature-dependent luminescence properties. The correlation between the luminescence thermochromism and the temperature-dependent variation of the Cu...Cu distance is also elucidated.