guanidiinien

Guanidine is a strongly basic organic compound with the chemical formula HNC(NH2)2. It is a colorless, crystalline solid that is soluble in water and polar organic solvents. Guanidine is a relatively strong base due to the resonance stabilization of its conjugate acid, the guanidinium ion. This ion has three equivalent resonance structures, distributing the positive charge over the nitrogen atoms and the central carbon.

Guanidine can be synthesized through various methods, including the reaction of dicyandiamide with ammonium nitrate or the reaction of thiourea with ammonia. It plays a crucial role in biological systems as a component of certain amino acids, most notably arginine. Arginine's side chain contains a guanidino group, which is essential for its function in protein structure and enzyme catalysis. The positively charged guanidinium group in arginine can form important ionic and hydrogen bonds.

Beyond its biological relevance, guanidine and its derivatives find applications in industry. Guanidine hydrochloride and guanidine thiocyanate are commonly used as chaotropic agents, meaning they can disrupt the hydrogen bonding network of water, leading to the denaturation of proteins. This property makes them valuable in molecular biology for protein extraction and nucleic acid isolation. Guanidine itself can also be used in the synthesis of various organic compounds and as a component in some pharmaceuticals.