Structure of 2,2',4,4',5,5'-hexamethoxybiphenyl

Structures of chlorinated methoxybiphenyls. II. 2,2',4,4',5',6-hexachloro-3-methoxybiphenyl

“…The degree of ortho substitution (2, 2', 6 and 6' positions) and the size of the substituents have been identified as the main causes of the twist angle observed in substituted biphenyls (Rissanen, Valkonen & Mannila, 1988;Chattopadhyay, Banerjee, Majumdar, Podder, Kashino & Haisa, 1987). Under some conditions n-electron overlap between adjacent molecules may sometimes contribute a small additional effect (Rissanen, Valkonen & Mannila, 1988).…”

“…The 0108-2701/88/040684-03503.00 orientation of the me.thoxy group is strongly affected by the substituents occupying the positions on either side of the methoxy-substituted benzene C atom. The methoxy group is coplanar or nearly coplanar with the phenyl ring when there is no or only one substituent present on the adjacent benzene C atoms (Rissanen, Valkonen & Mannila, 1988;Chattopadhyay et al, 1987), but it assumes a perpendicular orientation when there are substituents on both adjacent benzene C atoms (Rissanen, Valkonen & Knuutinen, 1987).…”

X-ray and spectroscopic investigation of 2-(2-hydroxyphenyl)pyridine-1-oxide

“…In comparison, orthosubstituted biphenyl derivatives in which the intramolecular hydrogen bond is not formed, show large deviations from coplanarity. For example, the two chlorine substituents in ortho positions in 2,2'-dichlorobiphenyl (Romming et at., 1974) cause a twisting angle of 66.8 ~ the two methoxy substitutents in 2,2',4,4',5,5'-hexamethoxybiphenyl -81.2(1) ~ (Chattopadhyay et al, 1987).…”

5,5′-Dichloro-2,2′-dimethoxybiphenyl

“…The corresponding dihedral angles of structurally related biphenyls, 2,2′dimethoxybiphenyls, 4,4′-dimethyl-2,2′,5,5′-dimethoxybiphenyl and 2,2′,4,4′,5,5′-hexamethoxybiphenyl, are comparable with 66.94 (7)°, 69.1° (no s.u. available) and 81.1 (1)°, respectively (Nakaema et al, 2008;Sun et al, 2001;Chattopadhyay et al, 1987). In the title compound, the methoxy group at C7′ has an almost coplanar arrangement with aromatic ring system, with a dihedral angle of 4.22 (18)°.…”

“…For background to polychlorinated biphenyls, see: Basu et al (2009); Hu et al (2008); Kaminsky et al (1981); Kennedy et al (1981); McLean et al (1996); Rodenburg et al (2010). For related structures, see: Chattopadhyay et al (1987); Nakaema et al (2008); Sun et al (2001). For the synthesis of the title compound, see: Joshi et al (2011).…”