Molecular gears: Structures of (9,10-triptyceno) crown ethers
The incorporation of 9,10-triptycene unit in a crown ether is examined from a structural perspective. Insertion of a triptycene group into 18-crown-6 stretches the crown into an ellipse, as seen in structures presented here of 9,10-triptyceno-22-crown-6 and its thallium complex. Symmetric addition of two triptycene groups into 18-crown-6 results in the sterically congested bis(9,10-triptyceno)-26-crown-6, whose crown cavity is filled with the {pi}-clouds of two arene groups. The larger bis(9,10-triptyceno)-32-crown-8 is more sterically relaxed. The structures of these bis(triptyceno)crown ether molecules are the first with two triptycene groups simultaneously linked through their 9 and 10 positions, thereby forming a simple molecular gearing mechanism. The compound 9,10-triptyceno-22-crown-6 crystallizes in the orthorhombic space group Pbca with a = 10.7962(7), b = 15.826(3), c = 31.147(5) {angstrom}, V = 5321.8(12) {angstrom}{sup 3}, and Z = 8; its complex with TlNO{sub 3} crystallizes in the monoclinic space group P2{sub 1}/c with a = 8.1884(14), b = 19.552(2), c = 20,575(4) {angstrom}, {beta} = 97.062(8){degree}, V = 3269.2(9) {angstrom}{sup 3}, and Z = 4; bis(9,10-triptyceno)-26-crown-6 crystallizes in the triclinic space group P{bar 1} with a = 8.6488(11), b = 10,7718(12), c = 12.3324(12) {angstrom}, {alpha} = 111.58(1), {beta} = 100.55(1), {gamma} = 106.43(1){degree}, V = 970.3(5) {angstrom}{sup 3}, and Z = 1; and bis(9,10-triptyceno)-32-crown-8 crystallizes in the orthorhombic space group Pna2{sub 1} with a = 20.186(3), b = 8.558(2), c = 25.623(2) {angstrom}, V = 4426.2(14) {angstrom}{sup 3}, and Z = 4.
- Research Organization:
- Oak Ridge National Lab., TN (US)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 20013133
- Journal Information:
- Journal of Chemical Crystallography, Vol. 29, Issue 5; Other Information: PBD: May 1999; ISSN 1074-1542
- Country of Publication:
- United States
- Language:
- English
Similar Records
Complexes with Hg(II) and macrocyclic ligands
[Bi{sub 12}O{sub 14}E{sub 12}]{sub n} columns and lone pairs E in Bi{sub 13}Mo{sub 4}VO{sub 34}E{sub 13}: Synthesis, crystal structure, and chemistry of the Bi{sub 2}O{sub 3}-MoO{sub 3}-V{sub 2}O{sub 5} system