The Influence of Dormitory Architecture On Resident Behavior

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66943/2/10.1177_001391657300500402.pd

Structures of potassium encapsulated within the 1,3-alternate conformation of calix[4]arenes

5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrakis(diethylcarbamoylmethoxy)calix[4]arene (L1) has been synthesised in the 1,3-alternate conformation for the first time. Proton NMR complexation studies suggest that this molecule forms 1:1 and 2:1 complexes with potassium cations. A crystal structure determination has been performed on the 2:1 complex [K2L1][CuCl2][I3], [monoclinic, space group P21/n, a= 13.972(6), b= 23.373(12), c= 25.271(12)Å, ?= 102.5(1)°, Z= 4, R= 0.092 for 6501 ‘observed’ reflections]. The structure of the 1:1 potassium complex of the related diamide, 5,11,17,23-tetra-tert-butyl-25,27-bis(diethylcarbamoylmethoxy)-26,28-dihydroxycalix[4]arene (L2), [KL2][I3], has also been elucidated [triclinic, space group P, a= 14.160(8), b= 16.326(10), c= 16.540(10)Å, ?= 65.83(1), ?= 67.37(1), ?= 88.87(1)°, Z= 2, R= 0.091 for 4976 ‘observed’ reflections]. Remarkably, the calixarene is again found in the 1,3-alternate conformation, although 13C NMR studies suggest that, in this case, the conformation is not maintained in solution. The co-ordination spheres of the potassium cations in both structures are similar, with a hitherto unobserved combination of close contacts to four oxygen atoms, and to two phenyl rings of the respective calix[4]arenes, Molecular mechanics calculations have been carried out to investigate the relative stabilities of the calixarene conformations

Studies of lead(II) complexes of substituted calix[4]arenediquininones: The remarkable self assembly of a Novel Redox Active 3 D Channel Network.

Several calix[4]diquinone–lead(II) complexes have been prepared. Two momonomeric complexes have been prepared with p-tert-butyl-(26,28-crown-5)calix[4]diquinone L1 and p-tert-butylcalix[4]diquinone bis(ethyl ether)L2, namely [PbL1(ClO4)2] and [PbL2(ClO4)2(H2O] wherein the metal atoms are 10-coordinate being bonded to the four oxygen atoms at the lower rim of the calixdiquinone and three perchlorate oxygen atoms together with three crown oxygen atoms or two carbonyl oxygen atoms and a water molecule respectively. By contrast the lead(II) complex with calix[4]diquinone bis(acid)L3 forms a unique trimeric [Pb9(L3– 2H)3(ClO4)6(OH)6] unit with crystallographic 3/m symmetry containing three unique Pb(II) atoms. One of these is to be found within the calix[4]diquinone bonded to the four oxygen atoms at the lower rim, two acid oxygen atoms, two perchlorate anions and a water molecule. The other two Pb(II) atoms are bonded to carbonylic oxygen atoms, water molecules and hydroxide ions. These trimeric units are interconnected via upper rim quinone oxygen–Pb(II) interactions to form a three-dimensional network containing channels of ca. 14 Å in diameter

Cation recognition by new diester- and diamide-calix[4]arenediquinones and a diamide-benzo-15-crown-5-calix[4]arene

The synthesis, metal, ammonium and alkyl ammonium cation coordination chemistry and electrochemical recognition studies of new diester-and diamide-calix[4]arenediquinone receptors are described. In addition the synthesis and coordination properties of a novel diamide benzo-15-crown-5-calix[4]arene molecule is reporte