Die kristallstruktur von oligo[(2‐hydroxy‐1,3‐phenylen)methylen]en

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Abstract
The crystal structure of three tetranuclear phenolic compounds – 6,6′‐bis (2‐hydroxy‐5‐methylbenzyl)‐4,4′‐dimethyl‐2,2′‐methylenediphenol (1), 6‐(2‐hydroxy‐3,5‐dimethylbenzyl)‐6′‐(2‐hydroxy‐5‐methylbenzyl)‐4,4′‐dimethyl‐2,2′‐methylendiphenol (2), and 6‐(3‐tert‐butyl‐2‐hydroxy‐5‐methylbenzyl)‐6′‐(2‐hydroxy‐5‐methylbenzyl)‐4,4′‐dimethyl‐2,2′‐methylene‐diphenol (3) –, was determined by single crystal X‐ray analysis. Intramolecular hydrogen bonds between all hydroxyl groups of adjacent phenolic units are found for all molecules. They are directed to the opposite end of the molecule by the ortho‐methyl or ortho‐tert‐butyl group in compounds 2 and 3, while no special orientation is found in 1. The conformation of the phenolic units is trans/trans (anti/anti) in 1 and cis/trans (syn/anti) in 2 and 3. Consequently, in the crystal lattice, 2 and 3 form cyclic dimers via intermolecular head‐to‐tail hydrogen bonds, while the molecules of 1 are arranged to chains of indefinite length by head‐to‐head and tail‐to‐tail hydrogen bonds.