A highly selective vapochromic methanol sensor based on one step synthesis of a simple platinum terpyridine complex

A novel and simple luminescent methanol sensor, [Pt(Cl-4-terpy)Cl]Cl (2) (Cl-4-terpy = 4-Chloro-2,2':6',2 ''-terpyridine), has been synthesized in good yield over 85%. Complex 2 was studied spectroscopically in both fluid solution and solid state. At room temperature, it is observed that 2 is weak emissive maximized at 612 nm in fluid solution and brightly luminescent maximized at 655 nm in the solid state. At 77 K, the solid state of 2 shows different properties, with two obvious peaks maximized at 590 and 675 nm. The complex exhibits reversible vapochromic behavior upon exposure to methanol vapors, changing color from red to yellow, with a blue shift in the emission from 655 to 615 nm, resulting from the disruption of intermolecular Pt center dot center dot center dot Pt interactions by methanol vapor. The vapochromic sensor also shows high selectivity for only methanol vapors among all the general available volatile organic compounds (VOCs) in the lab, even in the presence of water, and fast response (color change in less than 1 s). (C) 2010 Elsevier B.V. All rights reserved.