
TY  - JOUR
A1  - Bott, Raymond C. 
A1  - Smith, Graham 
A1  - Wermuth, Urs D. 
A1  - Dwyer, Nathan C. 
T1  - Molecular Cocrystals of Aromatic Carboxylic Acids with Unsymmetrically Substituted Ureas. The Structures of Phenylurea and the 1 : 1 Adducts of Phenylurea with a Series of Nitro-Substituted Acids
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 2000
VL  - 53
IS  - 9
SP  - 767
EP  - 777
KW  - Phenylurea; nitrobenzoic acid; nitrosalicylic acid; adduct; infrared spectroscopy; X-ray crystal structure.
UR  - https://doi.org/10.1071/CH00099 
N2  - The crystal structure of phenylurea (1), &#91;(C7H8N2O)&#93;, has been determined and revealed a simple cyclic dimer involving hydrogen bonding between the two nitrogen atoms of one molecule and the oxygen atom of a second molecule. The system is completed by a hydrogen bond between the non-substituted nitrogen atom of a third molecule and the oxygen atom of the second molecule to form a chain polymer. The 1 : 1 molecular adducts of phenylurea with 2-nitrobenzoic acid, &#91;(C7H5NO4)(C7H8N2O)&#93; (2), 3-nitrobenzoic acid, &#91;(C7H5NO4)(C7H8N2O)&#93; (3), 3,5-dinitrobenzoic acid, &#91;(C7H4N2O6)(C7H8N2O)&#93; (4), 2,4,6-trinitrobenzoic acid, &#91;(C7H3N3O8)(C7H8N2O)&#93; (5), 5-nitrosalicylic acid, &#91;(C7H5NO5)(C7H8N2O)&#93; (6), and 3,5-dinitrosalicylic acid, &#91;(C7H4N2O7)(C7H8N2O)&#93; (7) have been prepared and characterized by infrared spectroscopy and, for compounds (2), (4), (5) and (6), by single crystal X-ray diffraction methods. The adduct involving phenylurea and 4-nitrobenzoic acid could not be isolated from this system. In all examples, cyclic hydrogen-bonding interactions are found between the phenylurea and the carboxylic acid groups. All display further peripheral hydrogen bond associations that result in the formation of predominantly simple chain polymeric structures. 
ER  -

