A rapidly-reversible absorptive and emissive vapochromic Pt(II) pincer-based chemical sensor

Selective, robust and cost-effective chemical sensors for detecting small volatile-organic compounds (VOCs) have widespread applications in industry, healthcare and environmental monitoring. Here we design a Pt(II) pincer-type material with selective absorptive and emissive responses to methanol and water. The yellow anhydrous form converts reversibly on a subsecond timescale to a red hydrate in the presence of parts-per-thousand levels of atmospheric water vapour. Exposure to methanol induces a similarly-rapid and reversible colour change to a blue methanol solvate. Stable smart coatings on glass demonstrate robust switching over 104 cycles, and flexible microporous polymer membranes incorporating microcrystals of the complex show identical vapochromic behaviour. The rapid vapochromic response can be rationalised from the crystal structure, and in combination with quantum-chemical modelling, we provide a complete microscopic picture of the switching mechanism. We discuss how this multiscale design approach can be used to obtain new compounds with tailored VOC selectivity and spectral responses

Platinum Complexes of Rigid Bidentate Phosphine Ligands in the Hydroformylation of 1-Octene

The synthesis of the two novel diphosphine compounds 1,2-bis(3-(diphenylphosphino)-4-methoxyphenyl)benzene (1; Terphos), and 1,2-bis(2-diphenylphosphino)benzene (2), both derived from a terphenyl backbone structure, are described. Straightforward synthetic routes have been employed to obtain these ligands in good yields from cheap starting materials. The coordination of ligands 1 and 2 with PtCl2(cod) has been studied by NMR spectroscopy, and the X-ray crystal structures of the resulting complexes 4 and 5 were determined. The 31P NMR spectra of the mononuclear products demonstrate solely cis coordination for both bidentate ligands, with corresponding coupling constants JPt-P of 3810 Hz (cis-[PtCl2(1)], complex 4) and 3712 Hz (cis-[PtCl2(2)], 5). The bite angles P1-Pt-P2 were 98.74 and 105.89°, respectively, in the distorted square-planar complexes. The new diphosphines have been applied in the platinum/tin-catalyzed hydroformylation of 1-octene, and both ligands give active and selective platinum catalysts