Crystal and Molecular Structure of the bis-Ethyl Urethane of 5,7-Dodecadiyn-1,12,diol (ETCD)

Abstract

Grown from ethyl acetate solution, the bis-ethylurethane of 5,7-dodecadiyn-1,12-diol is a monoclinic crystal, a = 16.9740(16), b = 4.9770(5), c = 11.0874(11) Å; β = 101.869(6)°; Z = 2; V = 916.63(16) ų. The crystal structure contains two N─H…O hydrogen bonds per molecule and has nearly ideal parameters (d = 4.977 Å, ϕ = 45.8°, R = 3.477 Å) for solid-state polymerization.

Keywords:

• Diacetylene monomer
• crystal structure
• thermochromic polydiacetylenes

Acknowledgements

We thank the National Science Foundation (Grants DMR-0504000 and CHE-0521047) for partial support of this research, and the Faculty Student Collaborative Research Program for partial support of Xiaoyu Wang during Summer 2005 and 2006.

Notes

^a R = Σ | | F _o | −| F _c | |/Σ | F _o |

^b R _w = [Σ w(| F _o |²− | F _c |²)²/Σ w(F _o ²)²]^1/2

^c S = [Σ w(| F _o |²−| F _c |²)²/(n−p)]².

a = (2−x, −y, −z)