Hydrogen compounds are only required to contain carbon. However, most of them also contain hydrogen, and because it is the carbon-hydrogen bond which gives this class of compounds most of its particular chemical characteristics, carbon-hydrogen bonds are required in some definitions of the word "organic" in chemistry. Millions of hydrocarbons are known, and they are usually formed by complicated synthetic pathways that seldom involve elementary hydrogen. Compounds of hydrogen are often called hydrides, a term that is used fairly loosely. The term "hydride" suggests that the H atom has acquired a negative or anionic character, denoted H, and is used when
Carbon diselenide Carbon diselenide Carbon diselenide is an inorganic compound with the chemical formula CSe. It is a yellow-orange oily liquid with pungent odor. It is an analogue of carbon disulfide (CS). This light-sensitive compound is insoluble in water and soluble in organic solvents. Carbon diselenide is a linear molecule with D symmetry. It is produced by reacting selenium powder with dichloromethane vapor near 550 °C. It was first reported by Grimm and Metzger, who prepared it by treating hydrogen selenide with carbon tetrachloride in a hot tube. Like carbon disulfide, carbon diselenide polymerizes under high pressure. The structure of the polymer