Mo+calix+Schiff+base++J.+Atwood+revised+submission.pdf (392.81 kB)
Download fileMolybdocalix[4]arene N,O-Schiff base ligands
journal contribution
posted on 2017-11-16, 13:51 authored by Xue Wang, Ke-Qing Zhao, Mark ElsegoodMark Elsegood, Carl RedshawThe ‘one-pot’ reaction of 2-hydroxy-3,5-di-tert-butylsalicylaldehyde with in-situ generated
‘amino calixarene’ (from {Mo[(2-NC6H4)2CH2CH2]Cl2(DME)}, KOtBu and tbutylcalix[4]areneH4 LH4) afforded, after work-up, the heterobimetallic salt K(NCMe)2[Mo(NCMe)(OEt)(2-C6H4CH2CH2C6H4NH2-2)L] (1∙2MeCN). By constrast, use of the ‘amino calixarene’ [Mo(NCMe)(2-C6H4CH2CH2C6H4NH2-2)L]
afforded the potassium/ethoxide-free complex [Mo(NCMe)(2-C6H4CH2CH2C6H4N-2-CHC6H2-2/-(OH)-3/,5/-tBu)L] (2∙2MeCN). Reaction of 2 (two equivalents) with the dialdehyde [1,3-(CHO)2-5-MeC6H3OH-
2] led, following work-up, to the isolation of the cation-anion pair [C46H42N4O2]
2+[Mo6O19]2-·C2H3N (3). The molecular structures of 1·2MeCN, 2·2MeCN and 3·MeCN are reported, for which it was necessary to
use synchrotron radiation for data collection. Complex 1 contains an eliptical calixarene conformation as a result of π-interactions between the K+ and the arene groups and a distorted O5N octahedral geometry at the
molybdenum centre, whereas in ‘K+
/ethoxide-free’ 2, the calixarene retains the cone conformation and the metal possesses a distorted octahedral O4N2 coordination environment. In 3, a protonated macrocyclic
cation, formed via hydrolysis, has weak intermolecular interactions with the polyoxomolybdate anion.
Funding
Sichuan Normal University and the National Natural Science Foundation of China (grants 51443004 and 51273133) are thanked for financial support
History
School
- Science
Department
- Chemistry