Synthesis and crystalline state photochromism of 3,3′-diaryl biindenylidenedione derivatives

Unexpected cleavage and formation of C–C bonds by the nitration of 2,2′-biindanyl-1,1′,3,3′-tetraone

A novel compound, triindanylhexaone, is formed unexpectedly as a major product from the nitration of 2,2′-biindanyl-1,1′,3,3′-tetraone. The structure was clearly established by X-ray crystallography. The reaction mechanism is interpreted as involving an oxidation-induced radical addition.

Developments toward the synthesis and application of 3-hydroxyindanones

3-Hydroxyindanone is an important scaffold in many natural products, biologically active compounds, and functional materials. This review provides a comprehensive overview of the construction of 3-hydroxyindanone derivatives and their applications towards pharmaceutically promising drug candidates.

Synthesis and Photochromic Properties of 3,3′-Dihydroxy-6,6′(or 7,7′)-Dimethyl-3,3′-Dipropyl-[2,2′-bi-1H-indenylidene]-1,1′-Dione

3,3′-Dihydroxy-6,6′(or 7,7′)-dimethyl-3,3′-dipropyl-[2,2′-bi-1H-indenylidene]-1,1′-dione was found to undergo photochromism in a single crystalline phase from yellow to red. The structure of the compound was confirmed by X-ray crystallography analysis. Results showed that the compound contains a pair of isomers, 3,3′-dihydroxy-6,6′-dimethyl-3,3′-dipropyl-[2,2′-bi-1H-indenylidene]-1,1′-dione and 3,3′-dihydroxy-7,7′-dimethyl-3,3′-dipropyl-[2,2′-bi-1H-indenylidene]-1,1′-dione. A plausible reaction mechanism was proposed.

Organic Photochromic Radical Compound Based on a Biindenylidene System

A novel dual functional biindenylidene derivative (4) having nitronyl nitroxide radicals on both sides of the molecules, was synthesised. Its photochromism, as well as magnetic properties were investigated. The compound 4 underwent photochromic reactions by irradiation with UV and visible light. The intermolecular magnetic interactions were measured with a SQUID susceptometer.

Photochromism and Crystal Structure of 3,3′-dimethyl-3,3′-dihydroxy-5, 5′-dimethyl-2,2′-bi-1H-indanylidene-1,1′-dione

A novel photochromic compound, 3,3′- dimethyl-3,3′-dihydroxy-5,5′-dimethyl -2,2′-bi-1H-indanylidene-1,1′-dione (I), was synthesised and its structure was determined by X-ray crystallography. The compound exhibited reversible photochromism, and a stable organic radical was generated which was detected by electron spin resonance spectroscopy.