Hexakis(urea-κO)zinc(II) dinitrate at 110 and 250â
K: uniaxial negative thermal expansion.
Acta Crystallogr C
; 67(Pt 2): m50-5, 2011 Feb.
Article
in En
| MEDLINE
| ID: mdl-21285496
ABSTRACT
The crystal structure of the title compound, [Zn{CO(NH(2))(2)}(6)](NO(3))(2), has been determined at 110 and 250â
K. The structure is stabilized by 12 individual hydrogen bonds, both intra- and intermolecular. Analysis of the thermal expansion tensor, based on unit cells determined over a temperature range of 180â
K, shows uniaxial compression in the direction of the b axis during warming. The hydrogen bonds form layers perpendicular to this axis and these layers are connected by coordinative bonds parallel to the axis. As expected, the intermolecular hydrogen bonds expand during warming. Surprisingly, the coordinative bonds contract, accompanied by changes in the O-Zn-O angles. Overall, this behaviour can be described as an accordion-like effect.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Organometallic Compounds
/
Zinc
Language:
En
Journal:
Acta Crystallogr C
Year:
2011
Document type:
Article
Affiliation country:
Netherlands