444878-67-5Relevant articles and documents
The interconversion of dichlorobis(N-n-propylsalicylaldimine)zinc(II) and bis(N-n-propylsalicylaldiminato)zinc(II)
Torzilli, Michele A.,Colquhoun, Shalton,Doucet, Danielle,Beer, Robert H.
, p. 697 - 704 (2002)
The interconversion of the zinc(II) complex of the neutral ligand adduct of N-n-propylsalicylaldimine Zn(LprH)2Cl2 and its salicylaldiminato counterpart Zn(Lpr)2 is investigated. The compound Zn(LprH)2Cl2 is prepared by the reaction of anhydrous ZnCl2 with 2 equiv. of N-n-propylsalicylaldimine (LprH) in benzene. A crystallographic study of the distorted tetrahedral Zn(LprH)2Cl2 adduct reveals that the oxygen atom of the ligand is deprotonated and bound to the zinc atom while the nitrogen is protonated and non-coordinating. An infrared spectrum of Zn(LprH)2Cl2 exhibits a C=N stretch at a higher energy (1658 cm-1) than the free ligand (1632 cm-1) consistent with the presence of the iminium moiety. In contrast, the deprotonated ligand of the crystallographically characterized salicylaldiminato complex Zn(Lpr)2 coordinates to zinc in its prototypical bidentate monoanionic coordination mode. Deprotonation of Zn(LprH)2Cl2 with Et3N or NaOH forms Zn(Lpr)2. The reverse reaction, protonation of Zn(Lpr)2 with anhydrous HCl, produces Zn(LprH)2Cl2. These reactions demonstrate the interrelationship between the zinc salicylaldimine adduct and its corresponding salicylaldiminato complex.
