Triple Inclusion by a Calixarene: the CrystaL Structure of the Europium(III) Complex of Bis(homooxa)‐p‐tert‐butylcalix[4]arene

Abstract

41 a) 1 crystallizes monoclinically, P2,/c; a = 12.465(1), b = 15.786(1), c = 17.629(2) A, B = 96.62(1)", Z = 4, 5039 independent reflections (Mo,,: 1.5" I 0 I 25.0"), 3651 observed with 1 2 2 4 0 ; 343 parameters, R = 0.064, Rw = 0.078 [4d]; b) 2: P2,/n; a = 13.019(2), b = 17.586(3), c = 18.557(3)A, / 3 = 106.62(1)", Z = 4, 4751 independent reflections (Mo,, 0.5" I 0 I22.5") 3981 observed with 1 2 241); 424 parameters, R = 0.045, R , = 0.055 [4d]; c) 3: triclinic, Pi; a = 12.724(8), b = 2 = 2, 5690 independent reflections (Mo,,: 1.5" 9 0 I 22.5"). 3649 observed with 1 2 2 4 0 ; 383 parameters, R = 0.058, R, = 0.060 [4d]. d) Solution and refinement of structures with the program systems SHELXS-86, SHELX-76.

Homooxacalixarenes: II. Receptor properties

“…The macrocyclic ligand in the complex has a cup form each of which includes a DMSO molecule. The structure of the complex is similar to that of the dimer complex of monooxacalix [4]arene 37 with Eu [35].…”

Hydrated Lanthanoid Complexes of 5-(2′-Pyridyl)tetrazole Formed in the Presence of Dimethyl Sulfoxide

“…n DMSO, 14 as reported previously for the synthesis of lanthanoid calixarene complexes. 9,[15][16][17] Reaction of these solvates with pytz and triethylamine in organic solvents resulted in the unexpected crystallisation of hydrates, confirmed by the structural characterisation of [Eu(pytz)3(H2O)3]. Decreasing the metal:ligand ratio resulted in the crystallisation of the novel system [Y(pytz)2(H2O)4](pytz).…”

A 1:1:1 chloroform/tetrahydrofuran solvate ofp-tert-butyltetrahomodioxacalix[4]arene

“…The inclusion of two chemically different solvent molecules in a calixarene cavity is a somewhat uncommon feature, at least for small calixarenes [in both compounds (II) and (III), two identical molecules were included, acetonitrile in (II), pyridine in (III)]. It has been suggested that the ability of calixarenes to hold two different species relatively close one to the other was indicative of their potential as`enzyme mimics' (Asfari et al, 1991). The location of the chloroform H atom is indicative of a possible hydrogen bond with the O atom of tetrahydrofuran.…”