2,2'-Dithio-dianiline: a redetermination at 100 K

Area of Science:

• Crystallography
• Materials Science
• Chemical Physics

Background:

• Previous structural studies of 2,2'-(disulfanedi-yl)dianiline were conducted at room temperature.
• Existing literature describes intra- and inter-molecular N-H⋯S hydrogen bonding for this compound.

Purpose of the Study:

• To clarify the nature of intra- and inter-molecular hydrogen bonding in 2,2'-(disulfanedi-yl)dianiline.
• To investigate the structural changes upon cooling to 100 K.

Main Methods:

• X-ray crystallography at low temperature (100 K).
• Analysis of unit cell dimensions and atomic positions.
• Refinement of hydrogen atom positions.

Main Results:

• Unit cell contraction observed upon cooling, most pronounced along the c-axis.
• Confirmation and clarification of N-H⋯S hydrogen bonding.
• Identification of N-H⋯N hydrogen bonds forming 2D frameworks parallel to the ab plane.
• Establishment of additional inter-molecular N-H⋯S hydrogen bonds.
• Observation of inter-molecular C-H⋯π interactions contributing to crystal stabilization.

Conclusions:

• The low-temperature redetermination provides a clearer understanding of hydrogen bonding in the crystal structure.
• The crystal structure is stabilized by a combination of N-H⋯N, N-H⋯S hydrogen bonds, and C-H⋯π interactions.