BẢN CHẤT CỦA hợp chất cơ và ORGANOMETALLOID Một hợp chất hữu cơ là một trong trong đó các nguyên tử kim loại liên kết với ít nhất một nguyên tử carbon trong một nhóm hữu cơ. Một hợp chất organometalloid là một hợp chất trong đó một nguyên tố kim đồng là ngoại quan đến ít nhất một nguyên tử carbon trong một nhóm hữu cơ. Các yếu tố kim đồng được thể hiện trong bảng tuần hoàn các nguyên tố trong hình và bao gồm bo, silicon, germanium, asen, antimon, tellurium, và astatine (một nguyên tố phóng. | Chapter 12 Organometallics and Organometalloids THE NATURE OF organometallic and ORGANOMETALLOID compounds An organometallic compound is one in which the metal atom is bonded to at least one carbon atom in an organic group. An organometalloid compound is a compound in which a metalloid element is bonded to at least one carbon atom in an organic group. The metalloid elements are shown in the periodic table of elements in Figure and consist of boron silicon germanium arsenic antimony tellurium and astatine a very rare radioactive element . In subsequent discussions organometallic will be used as a term to designate both organometallic and organometalloid compounds and metal will refer to both metals and metalloids unless otherwise indicated. Given the predominance of the metals among the elements and the ability of most to form organometallic compounds it is not surprising that there are so many organometallic compounds and new ones are being synthesized regularly. Fortunately only a small fraction of these compounds are produced in nature or for commercial use which greatly simplifies the study of their toxicities. A further clarification of the nature of organometallic compounds is based on the electronegativities of the elements involved . the abilities of covalently bonded atoms to attract electrons to themselves. Electronegativity values of the elements range from for cesium to for fluorine. The value for carbon is and all organometallic compounds involve bonds between carbon and an element with an electronegativity value of less than . The value of the electronegativity of phosphorus is but it is so nonmetallic in its behavior that its organic compounds are not classified as organometallic compounds. Organometallic compounds are very important in environmental and toxicological chemistry. The formation of organometallic species in the environment such as occurs with the methylation of mercury by anaerobic bacteria in .
