Correlation of Crystal Parameter with Vibrational Data of New Three Tetramethylammonium Salts

S Ghammamy,H Sahebalzamani,Sadjad Sedaghat

doi:10.12944/cwe.7.1.11

Abstract

Examination of the solid state infrared spectra of the tetramethylammoniumcation in salts shows correlation of infrared spectral properties with C-H···X hydrogen bonding and crystal habits in these tetramethylammonium salts. The IR predicted crystal habits are comprised by experimental and theoretical data. A good relation between three data has been found. The C-H stretching region characteristic hydrogen bonding shifts in the above salts. In this research three complexes of tetramethylammoniumcation have been synthesized and the structures of them have been analyzed by correlation of vibrational data with crystal structures. These correlation shows that crystal symmetry (Tetrahedral), cation distortion (undistorted), site symmetry (D 2 d), unite cell symmetry (D4h 7 ) for (CH3)4NPF6 and crystal symmetry (Tetrahedral), cation distortion (distorted), site symmetry (D 2 d), unite cell symmetry (D 4 h7) for (CH 3 ) 4 NOH and crystal symmetry (Tetrahedral), cation distortion (undistorted), site symmetry (D2d), unite cell symmetry (D4h 7 ) for (CH 3 ) 4 NF.

Highlights

Tetramethylammonium compounds have many applications in science and biology
Many studies had been done on the vibrational spectra of tetramethylammonium salts and ahowed that it possible to correlate of infrared spectral properties with C-H...X hydrogen bonding and crystal habit in tetramethylammonium salts such as Harmon et al, 4-6
On the base of these studies founds that the C-H stretching region gives characteristic hydrogen bonding shifts in the tetramethylammonium salts; this effect is intense in the halideand hydroxidecompounds

Summary

Introduction

Tetramethylammonium compounds have many applications in science and biology. It is extremely difficult, if not impossible, to prepare single crystals of tetramethylammonium salts suitable for diffraction studies; the available methods of preparation give microcrystalline powders that are not suitable for X-ray single crystal diffraction. Many studies had been done on the vibrational spectra of tetramethylammonium salts and ahowed that it possible to correlate of infrared spectral properties with C-H...X hydrogen bonding and crystal habit in tetramethylammonium salts such as Harmon et al, 4-6.

Results

Conclusion