Synthesis, Structures and Properties of Silver(I) Coordination Polymers Based on Halogenated Cyanoformamidine

• Main Authors: Fu-Hung Cheng, 鄭富鴻
• Other Authors: Jhy-Der Chen
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/tc5r6n

碩士 === 中原大學 === 化學研究所 === 106 === The reactions of asymmetrical N’-4-halophenyl-N-cyanoformamidine (L-halo) with AgClO4 and AgNO3 afforded six coordination polymers: {[Ag(L-Cl)](ClO4)}n [(L-Cl = N-(4-chlorophenyl)-N′-cyanoformamidine)], 1; {[Ag(L-Br)](ClO4)}n [(L-Br = N-(4-bromophenyl)-N′-cyanoformamidine)], 2; {[Ag(L-I)2](ClO4)}n [(L-I = N′-cyano-N-(4-iodophenyl)-formamidine)], 3; {[Ag(L-F)](NO3) }n [(L-F = N′-cyano-N-(4-chlorophenyl)-formamidine)], 4; {[Ag(L-Cl)](NO3) }n, 5 and {[Ag(L-Br)](NO3) }n, 6. Complexes 1 and 2 are one dimensional helical chains, and 3 features a two dimensional layer with the (63)-hcb topology, while 4 - 6 are one dimensional linear chains linked by Ag…Ag interactions and hydrogen bonds. While each of the Ag(I) ions of complexes 1 and 2 are coordinated by two different nitrogen atoms from two L-halo ligands, these ions are also interacted with two oxygen atoms of two perchlorate anions, resulting in a distorted linear geometry. The metal center of 3 is coordinated with two nitrogen atoms and two iodo atoms from four L-I ligands to give a distorted tetrahedral geometry. In 4 - 6, each of the silver ions is coordinated with two different nitrogen atoms from two L-halo ligands, and one oxygen atom from nitrite anion, which is also interacted with oxygen atom of another nitrite anion, forming a distorted triangular planar geometry. The UV-vis absorption spectra of the four L-halo ligands and complexes 1 - 6 exhibit absorptions at 250 to 375 nm, which can be tentatively assigned as π→π* transition. Moreover, complex 3 shows another lowest absorption band at 400 – 470 nm. The emission spectrum of 3 exhibits a board bands at 510 nm upon excitation at 450 or 468 nm.