Abstract
Reaction of ZnCl2 with three molar equivalents of 3{5}-tert-butylpyrazole (HpztBu) yields [ZnCl(HpztBu)3]Cl (1). Treatment of 1 with an appropriate Ag(I) or Tl(I) salt gives [ZnCl(HpztBu)3]X (X− = BF4−, 4; X− = ClO4−, 5; X− = NO3−, 6; X− = CF3SO3−, 7; X− = PF6−, 8). Crystal structures of all of the complexes show a [ZnCl(HpztBu)3]+ cation, with (for 1 and 4-7) only small deviations from C3v symmetry, with the tert-butyl groups forming a bowl-shaped cavity on one face of the complex. The X− anion binds within this cavity, via hydrogen bonding to the three pyrazole N–H groups. For 8, the PF6− guest only interacts with two N–H donors, the third pyrazole ring being twisted away from the anion. We attribute this to steric repulsions between the third ligand and the PF6− anion, which is larger than the other guests used in this study. 1H, 13C and 19F NMR, ESMS and IR studies provide good circumstantial evidence for these structures being retained in solution, although the guest anions undergo rapid intermolecular exchange by NMR that cannot be frozen out above 190 K.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Journal of the Chemical Society, Dalton Transactions
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.