55-01-6Relevant academic research and scientific papers
The synthesis, separation, and crystal and molecular structures of the three bisphenols, an ethanol solvate of one of them, and of a minor by-product, 6,6',7,7'-tetrachloro-8,8'-methylenebis(4H-benzo-1,3-dioxin), prepared by condensation of formaldehyde with 3,4-dichlorophenol
Ferguson, George,McCrindle, Robert,McAlees, Alan James
, p. 779 - 785 (2007/10/02)
Samples of all the three of the expected bisphenols, 4,4',5,5'-tetrachloro-2,2'-methylenebisphenol (1) and the 3,4,4',5'- (2) and 3,3',4,4'-tetrachloro (3) isomers, and of a minor by-product, 5,5',6,6'-tetrachloro-8,8'-methylenebis(4H-benzo-1,3-dioxin) (4), have been isolated from the mixture formed by acid-catalyzed condensation of 3,4-dichlorophenol with one half of a molar equivalent of formaldehyde.In addition, the structures and solid state conformations of all four compounds, and of an ethanol solvate of 1, have been revealed by X-ray crystallographic studies.The three bisphenol (1, 2, 3) all crystallize in space group P1. as centrosymmetric hydrogen-bonded dimers, while the solvate, 1*EtOH, although it also belongs to space group P1, forms relatively open infinite bands of hydrogen-bonded molecules.Crystals of 4 belong to space group Fdd2 and the molecules have twofold crystallographic symmetry. Key words: X-ray crystallography, bisphenols, tetrachloro-2,2'-methylenebisphenols, tetrachloro-8,8'-methylenebis(4H-benzo-1,3-dioxin).
