Reaction of p-Bu(t)-calix[4]arene (H(4)L) with excess ZnEt(2) (tmeda)
in toluene affords the fully deprotonated, bis-calixarene complex, [Zn
(2)L(2)Et(2)(tmeda)(2)], with each ethyl group endo to a calixarene in
the cone conformation; reaction of 1,3-dimethyl ether p-Bu(t)-calix[4
]arene (H(2)L) with ZnEt(2) yields the mono-calixarene complex [Zn(2)L
'Et(2)], the calixarene adopting a doubly flattened partial cone confo
rmation.