Four closely related N-(3-benzoyl-4,5,6,7-tetra­hydro­benzo[b]thio­phen-2-yl)benzamides: order versus disorder, and similar mol­ecular conformations but different modes of supra­molecular aggregation, with a new disordered refinement of 2-amino-3-benzoyl-4,5,6,7-tetra­hydro­benzo[b]thio­phene

Sagar, B. K. and Yathirajan, H. S. and Rathore, Ravindranath S. and Glidewell, Christopher (2018) Four closely related N-(3-benzoyl-4,5,6,7-tetra­hydro­benzo[b]thio­phen-2-yl)benzamides: order versus disorder, and similar mol­ecular conformations but different modes of supra­molecular aggregation, with a new disordered refinement of 2-amino-3-benzoyl-4,5,6,7-tetra­hydro­benzo[b]thio­phene. Acta Crystallographica Section C, 74 (1). pp. 45-53. ISSN 2053-2296

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Abstract

Four closely related N-(3-benzoyl-4,5,6,7-tetra­hydro­benzo[b]thio­phen-2-yl)benzamides, bearing different substituents on the benzamide ring, have been synthesized and structurally characterized. In each of N-(3-benzoyl-4,5,6,7-tetra­hydro­benzo[b]thio­phen-2-yl)-3-fluoro­benzamide, C22H18FNO2S, (I), N-(3-benzoyl-4,5,6,7-tetra­hydro­benzo[b]thio­phen-2-yl)-4-chloro­benzamide, C22H18ClNO2S, (II), N-(3-benzoyl-4,5,6,7-tetra­hydro­benzo[b]thio­phen-2-yl)-2,6-di­fluoro­benzamide, C22H17F2NO2S, (III), and N-(3-benzoyl-4,5,6,7-tetra­hydro­benzo[b]thio­phen-2-yl)-2-meth­oxy­benzamide, C23H21NO3S, (IV), the last of which crystallizes with Z′ = 2 in the space group P[\overline{1}], the fused six-membered ring adopts a half-chair conformation. In each of (I)–(III), this ring is disordered over two sets of atomic sites having occupancies of 0.811 (6) and 0.189 (6) in (I), 0.645 (7) and 0.355 (7) in (II), and 0.784 (6) and 0.216 (6) in (III), such that the two disorder components of the ring are almost enanti­omeric. Mol­ecules of (I) are linked into chains by π–π stacking inter­actions, and those of (II) are linked into chains by a C—H⋯π hydrogen bond. A combination of two C—H⋯O hydrogen bonds and two C—H⋯π hydrogen bonds links the mol­ecules of (III) into complex sheets, but the mol­ecules of (IV) are linked by a combination of two hydrogen bonds, one each of the C—H⋯O and C—H⋯π types, to form centrosymmetric tetra­mers. The structures of (I)–(IV) are compared with that of the unsubstituted analogue N-(3-benzoyl-4,5,6,7-tetra­hydro­benzo[b]thio­phen-2-yl)benzamide and a new refinement of the parent amine 2-amino-3-benzoyl-4,5,6,7-tetra­hydro­benzo[b]thio­phene, using the original data set, has found that here too the fused six-membered ring exhibits conformational disorder, with occupancies of 0.887 (9) and 0.113 (9). Comparisons are made with some related compounds.

Item Type:	Article
Uncontrolled Keywords:	synthesis, benzobthiophenes, crystal structure, molecular conformation, conformational disorder, hydrogen bonding, supramolecular assembly, pi-pi stacking
Subjects:	C Chemical Science > Chemistry
Divisions:	Department of > Chemistry
Depositing User:	C Swapna Library Assistant
Date Deposited:	13 Nov 2019 05:11
Last Modified:	13 Nov 2019 05:11
URI:	http://eprints.uni-mysore.ac.in/id/eprint/9992

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