Urea CAS：57-13-6

Urea possesses a flat molecular structure in its crystalline state, yet the nitrogen atoms take on a pyramidal shape in its lowest-energy gas-phase form. 

This unique structural duality gives rise to its special physical and chemical characteristics. 

In solid urea, the oxygen atom forms two N-H-O hydrogen bonds, creating a compact and thermodynamically stable hydrogen-bond network. This network disrupts ideal molecular stacking, resulting in an open framework composed of ribbon-like structures that form square-shaped channel cavities. 

The carbon atom in urea is sp² hybridized, which gives the C-N bonds significant double-bond characteristics. Meanwhile, the carbonyl oxygen in urea shows stronger basicity compared to that in formaldehyde and similar compounds. 

Urea dissolves readily in water because it can form extensive hydrogen bonds with water molecules, making it widely applicable in numerous industrial and chemical applications.

In mammals, urea functions as a key substance that regulates the excretion of nitrogen from the body. Produced in the liver during the decomposition of proteins, it is eventually removed from the body through urinary excretion. 

Urea also exists naturally in the skin, where it acts as both a moisturizing ingredient and a diuretic compound. In practical applications, urea is widely used to denature proteins and serves as a mild solubilizer for insoluble or denatured protein samples. It is especially effective in refolding proteins from materials denatured by 6 M guanidine chloride, such as inclusion bodies. 

Moreover, urea can be combined with guanidine hydrochloride and dithiothreitol (DTT) to help denatured proteins refold back into their natural and active structures.

Urea Chemical Properties

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