Solvothermal synthesis and theoretical study of a polypyridium

trimesylate adduct

YULAN ZHU^a,b,*, FENG MA^a,b, KUIRONG MA^a, LICAO^a and LIANHUA ZHAO^b

^aJiangsu Key Laboratory for Chemistry of Low-dimensional Materials, School of Chemistry

and Chemical Engineering, Huaiyin Normal University, Huai’an 223300, P R China

^bDepartment of Chemistry, Science College, Yanbian University, Yanji 133002, P R China

e-mail: yulanzhu2008@126.com

MS received 6 December 2010; accepted 17 May 2011

Abstract. The title compound (C₉H₃O₆·C₂₀H₁₇N₄)₄·0.5H₂O 1 was isolated from solvothermal synthesis of

4′-(4-pyridyl)-2,2′:6′,2′-terpyridine (pytpy) and trimesic acid (1,3,5-benzenetricarboxylic acid, H3BTC). It was

characterized by element analysis, IR, TGA, XRD, X-ray single-crystal diffraction, and spectroscopy properties,

together with quantum chemistry calculation of spectrum (UV–vis spectra) through the method b3lyp/6–31

t g (d,p) are also investigated. Single-crystal X-ray diffraction shows 1 possesses a 3-D supramolecular network

with 1-D six-fold helical double chains built from protonated cations and deprotonated

anions. The maximum of the fluorescent emission bands of 1 is located at 427 nm (λ_ex = 266 nm), with a

shoulder at about 390 nm. The result of theoretic calculations confirms that 1 has small HOMO–LUMO energy

gap (1.24 eV) and high chemical reactivity.

Graphical Abstract. The title compound (C₉H₃O₆∙C₂₀H₁₇N₄)₄∙0.5H₂O 1, possessing a 3-D

supramolecular network with 1-D six-fold helical double chains, was isolated

from solvothermal synthesis of 4′-(4-pyridyl)-2,2′:6′,2′-terpyridine (pytpy) and

trimesic acid (1,3,5-benzenetricarboxylic acid, H₃BTC). The result of

theoretical calculations confirms that 1 has small HOMO–LUMO energy gap

(1.24 eV) and high chemical reactivity.

Keywords. N-heterocyclic adduct; solvothermal synthesis; spectroscopy; DFT.