Side‐chain conformations in the isomorphous polyfluorinated {4, 4′‐bis[(2, 2‐difluoroethoxy)methyl]‐2, 2′‐bipyridine‐κ2N, N′}dichloridopalladium and ‐platinum complexes. Issue 11 (17th October 2017)

• Record Type: Journal Article
• Authors: Lu, Norman; Zheng, Jing-Hung; Lu, Yi-Jing; Chiang, Hsing-Fang; Chu, Chun-Wei; Thrasher, Joseph S.; Wen, Yuh-Sheng; Liu, Ling-Kang
• Is Part Of: Acta crystallographica. Volume 73:Issue 11(2017)
• Page Start: 930
• Page End: 936
• Publication Date: 2017-10-17
• Subjects: bifurcated hydrogen bonding -- fluorous weak interaction -- bipyridine complex -- supramolecular interaction -- synthon -- crystal structure; Crystallography -- Periodicals; Crystals -- Periodicals; 548.3
• DOI: 10.1107/S2053229617013857
• Languages: English
• ISSNs: 2053-2296

Abstract

Abstract : The structures of the palladium and platinum complexes of 4, 4′‐bis[(2, 2‐difluoroethoxy)methyl]‐2, 2′‐bipyridine are isomorphous and have –C(Hα )2 OC(Hβ )2 CF2 H side chains with H‐atom donors at the α and β sites. Molecules are associated into dimers and the dimers form columns, with alternating dimers reinforced by C—H…Cl hydrogen bonds and C—Hβ …F(—C) interactions. Abstract : The polyfluorinated title compounds, [ M Cl2 (C16 H16 F4 N2 O2 )] or [4, 4′‐(HCF2 CH2 OCH2 )2 ‐2, 2′‐bpy] M Cl2 [ M = Pd, (1 ), and M = Pt, (2 )], have –C(Hα )2 OC(Hβ )2 CF2 H side chains with H‐atom donors at the α and β sites. The structures of (1 ) and (2 ) are isomorphous, with the nearly planar (bpy) M Cl2 molecules stacked in columns. Within one column, π‐dimer pairs alternate between a π‐dimer pair reinforced with C—H…Cl hydrogen bonds (α, α) and a π‐dimer pair reinforced with C—Hβ …F(—C) interactions (abbreviated as C—Hβ …F—C, C—Hβ …F—C). The compounds [4, 4′‐(CF3 CH2 OCH2 )2 ‐2, 2′‐bpy] M Cl2 [ M = Pd, (3 ), and M = Pt, (4 )] have been reported to be isomorphous [Lu et al. (2012). J. Fluorine Chem. 137, 54–56], yet with disorder in the fluorous regions. The molecules of (3 ) [or (4 )] also form similar stacks, but with alternating π‐dimer pairs between the (α, β; α, β) and (β, β) forms. Through (C—)H…Cl hydrogen‐bond interactions, one molecule of (1 ) [or (2 )] is expanded into an aggregate of two inversion‐related π‐dimer pairs, one pair in the (α, α) form and the other pair in the (C—Hβ …F—C, C—Hβ …F—C) form, with the plane normals making an interplanar angle of 58.24 (3)°. Due to the demands of maintaining a high coordination number around the metal‐bound Cl atoms in molecule (1 ) [or (2 )], the ponytails of molecule (1 ) [or (2 )] bend outward; in contrast, the ponytails of molecule (3 ) [or (4 )] bend inward.