PH-controlled construction of Cu(I) coordination polymers: in situ transformation of ligand, network topologies, and luminescence and UV-vis-NIR absorption properties.
Two new complexes [Cu(I)(3)(L1)I(3)](n) (1, L1 = 2,5-bis(4-pyridyl)-1,3,4-oxadiazole) and [Cu(I)(3)(L2)I(2)](n) (2, L2 = 2,5-bis(4-pyridyl)-1,2,4-triazolate) are controllably formed by using aqueous ammonia to regulate the pH value of the reaction involving CuI and L1. Interestingly, L2 of 2 is in situ generated from the ring transform of L1 when increase the pH value of the reaction. 1 exhibits 2-D layer, while 2 shows 3-D MOFs with a novel 3-nodal 4,4,5-connected net topology of an unprecedented Point (Schlafli) symbol: (4·5(2)·6(2)·7)(5(4)·8(2))(4(3)·5·6(6)). Although both 1 and 2 are built of CuI and similar ligands, different arrangements of CuI chains and ligands endow them with different physical properties. 1 displays a strong pure red luminescence emission, while 2 is nonluminescent and shows a broad absorption band covering the whole UV-vis-NIR spectrum range. The emissive excited states of 1 and the charge transitions of the optical absorption for 2 are solved by DFT calculations.
The State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, the Chinese Academy of Sciences, Fuzhou, Fujian, 350002, PR China.
Zhen-Lan
ZL
Fang
Jian-Gang
JG
He
Qi-Sheng
QS
Zhang
Qi-Kai
QK
Zhang
Xiao-Yuan
XY
Wu
Rong-Min
RM
Yu
Can-Zhong
CZ
Lu