Trifluoromethanesulfonamide: X-ray single-crystal determination and quantum chemical calculations

Abstract

The X-ray single-crystal structure of 1,1,1-trifluoromethanesulfonamide (triflamide) CF 3 SO 2 NH 2 , which is the ancestor of a large family of its derivatives, has been determined. The crystal structure is composed of infinite layers with an interlayer distance of 3.4 Å. Geometry optimization at the Møller-Plesset (MP2) and density functional theory (DFT) level showed the calculated bond distances to be, as a rule, longer than the experimental ones. A trial to simulate crystal packing effect on the geometrical parameters by calculating the dimer of triflamide in the gas phase failed -the starting X-ray geometry of the 'dimeric' unit with one NH···O=S H-bond -was optimized to the cyclic dimer with two H-bonds. However, when the external (crystal) field effect was simulated using the polarizable continuum model, the experimental geometry of the 'dimeric' fragment was satisfactorily reproduced. Calculations of the heptamer cluster having the structure of the hexagon with six triflamide molecules in vertices and one in the middle nicely reproduce the X-ray structure and brings the geometrical parameters closer to the experiment.

A Combined XPS and Computational Study of the Chemical Reduction of BMP‐TFSI by Lithium

“…[70] Larger fragments of TFSI such as Li 2 NSO 2 CF 3 , Li 2 N(CF 3 )(SO 2 ), LiN(CF 2 )(SO 2 ), LiNCF 2 , LiN(SO 2 ) 2 , Li 3 N-(SO 2 ) 2 , LiSO 2 CF 3 and LiSO 2 F were calculated assuming the space group P-1 with two molecules per unit cell, which has been reported for the structurally related compound trifluoromethanesulfonamide. [71] Calculations of Li 2 N-(SO 2 3 )(SO 2 CF 2 ) and Li 2 N(SO 2 CF 3 )(SO 2 ) employed orthorhombic unit cells including four molecules similar to the unit cell of the experimentally determined crystal structure of BMP-TFSI. [72] For the reduction products of BMP, simple orthorhombic structures with one molecule per unit cell were used as input structure, accounting for the fact that linear alkanes or alkylamines with longer side chains adopt crystal structures in which the alkyl chains are packed in a parallel fashion.…”

A Combined XPS and Computational Study of the Chemical Reduction of BMP‐TFSI by Lithium**

“…A crystalline structure of trilithium‐trisulfimide (LiNSO 2 ) was calculated adopting the crystal structure of triammonium‐trisulf‐imide [69] and the further reduced LiNSO was considered based on the crystal structure of the related tetramethylammoniumthionylimide [70] . Larger fragments of TFSI such as Li 2 NSO 2 CF 3 , Li 2 N(CF 3 )(SO 2 ), LiN(CF 2 )(SO 2 ), LiNCF 2 , LiN(SO 2 ) 2 , Li 3 N(SO 2 ) 2 , LiSO 2 CF 3 and LiSO 2 F were calculated assuming the space group P‐1 with two molecules per unit cell, which has been reported for the structurally related compound trifluoromethanesulfonamide [71] . Calculations of Li 2 N(SO 2 CF 3 )(SO 2 CF 2 ) and Li 2 N(SO 2 CF 3 )(SO 2 ) employed orthorhombic unit cells including four molecules similar to the unit cell of the experimentally determined crystal structure of BMP‐TFSI [72] .…”

“…[70] Larger fragments of TFSI such as Li 2 NSO 2 CF 3 , Li 2 N(CF 3 )(SO 2 ), LiN(CF 2 )(SO 2 ), LiNCF 2 , LiN(SO 2 ) 2 , Li 3 N-(SO 2 ) 2 , LiSO 2 CF 3 and LiSO 2 F were calculated assuming the space group P-1 with two molecules per unit cell, which has been reported for the structurally related compound trifluoromethanesulfonamide. [71] Calculations of Li 2 N-(SO 2 CF 3 )(SO 2 CF 2 ) and Li 2 N(SO 2 CF 3 )(SO 2 ) employed orthorhombic unit cells including four molecules similar to the unit cell of the experimentally determined crystal structure of BMP-TFSI. [72] For the reduction products of BMP, simple orthorhombic structures with one molecule per unit cell were used as input structure, accounting for the fact that linear alkanes or alkylamines with longer side chains adopt crystal structures in which the alkyl chains are packed in a parallel fashion.…”

Gas-Phase Structure of 3,7,9-tris(trifluoromethylsulfonyl)-3,7,9-triazabicyclo[3.3.1]nonane by GED and Theoretical Calculations

“…Minimal are the values for II and III at inward orientation of trifluoromethyl groups (see Introduction); maximal-for IV and V, but in chairs only. The experimentally measured X-ray values of Σ N are 358 • in 1 [1], i.e., the same as in 1,1,1trifluoromethanesulfonamide [7]. Another parameter of pyramidality/planarity is the angle between the CNC plane and N-S bond, which can be expressed via the S-N-X angle as (180 -S-N-X) and is given in Table 3.…”