Syntheses And Luminescent Properties Of Coordination Polymers Based On V-Shape N-Containing Ligands

The class of molecular-based materials can be easily obtained through self-assembly of multidentate organic ligands and metal ions, which have attracted more and more attention because of their intriguing structural diversity and potential applications as functional materials. In this paper, seven coordination polymers with novel structures were prepared and characterized by elemental analysis (EA), infrared spectra (IR), single-crystal X-ray diffraction, thermogravimetric analysis (TGA), fluorescence spectra and emission decay lifetimes.1. Five coordination polymers (CPs),{[Zn2(BPPA)2(BDC)2]·6H2O}n (1), {[Cd3(CBPPA)(BDC)2(DMF)2]·DMF·3H2O}n(2) (DMF=N,N-dimethylformamide), {[Zn(BPPA)(NDC)1/2(HCO2)]}n (3),{[Zn3(BPPA)3(TFBDC)3]·H2O}n (4) and {[Cd2(BPPA)2(TFBDC)2]}n (5) have been synthesized from the self-assembly of the"V-shape"BPPA ligand with Zn/Cd metal salts, incorporating coligands (H2BDC= 1,4-benzenedicarboxylic acid, H2NDC= 2,6-naphthalenedicarboxylic acid, TFBDC= 2,3,5,6-tetrafluoroterephthalic acid, BPPA= bis(4-(pyridine-4-yl)phenyl)amine, DMF = N,N-dimethylformamide). Compound 1 is a 4-fold interpenetrated three-dimensional (3D) network with sra topology. Compound 2 is the first 2-fold interpenetrated sxa topology, which is reported only non-interpenetration before. Compound 3 is a one-dimensional chain by utilizing a "longer" rigid H2NDC coligand. Via a"fatter" rigid TFBDC ligand, we control interpenetration by one-pot synthesis. Both compounds 4 and 5 are non-interpenetrated 3D 6T8 frameworks, and the 6T8 topology has rarely been reported in CPs before. Interestingly, carboxyl groups in 1-5 adopt various coordinate modes. Luminescent properties of 1-5 have also been explored, and the emission decay lifetimes of 4 and 5 are longer than compounds 1-3 and free ligands because of afluorescent synergistic effect.Two new coordination polymers (CPs),{[Co(BIPA)(trans-CHDA)]}n (6) and {[Co(BIPA)(1,3-BDC)]·2H2O}n (7) have been synthesized from the self-assembly of the "V-shape" BIPA ligand with Co metal salts, incorporating coligands (trans-HzCHDA= cyclohexane trans-1,3-dicarboxylic acid, 1,3-H2BDC= 1,3-benzenedicarboxylic acid, BIPA= bis(4-(1H-imidazol-1-yl)phenyl)amine). Compound 6 represents 3,5T1 topology. Compound 7 represents seh-3,5-P21/e topology. According to TTD/TTO database, the 2-fold interpenetrating seh-3,5-P21/c nets in 7 are quite different to the previous reported compounds with the same topology, which is reported only non-interpenetration before.