#molecular structure

• Aggregation — A form of union, grouping, or close association of multiple independent elements, statistical data, cells, or mineral particles into a single mass, without completely losing their chemical or structural individuality. In sociology, it represents a temporary or permanent collective formation based on individuals alignment.
• Allelotropic — Pertaining to or characterized by allelotropism; defined by the coexistence of two tautomeric or isomeric forms in dynamic equilibrium, continuously and reciprocally transforming into one another within the same phase. In a molecular structural sense, it describes the unstable or environment-dependent behavior of certain compounds whose chemical bonds reversibly reorganize under the direct influence of temperature or ambient pressure.
• Alloisomerism — A particular type or atypical form of isomerism in which chemical substances possess the same crude molecular formula and the same fundamental bonds, but differ structurally through spatial orientation, geometric configuration of substituents, or alternative atomic arrangement. This phenomenon causes significant differences in the physical, chemical, and biological properties of the respective compounds, being essential in drug synthesis.
• Allotropy — A property or structural phenomenon whereby a single chemical element, in its pure state (simple substance), can exist in two or more distinct molecular forms or crystalline structures, possessing completely different physical and often chemical properties (for instance, carbon existing as diamond, graphite, graphene, or fullerenes). The term applies strictly to elements, being the equivalent of polymorphism in mineralogy.
• Allotropism — A state, property, or structural phenomenon consisting of the capacity of a pure chemical element to exist under several distinct molecular forms or crystalline lattices (allotropy); the set of spatial geometric modifications that the atoms of the same simple substance can adopt, generating substances with totally different physical and mechanical properties, although the raw elemental composition remains identical.
• Amphions — An atypical plural form or regional biochemical variant designating amphions (zwitterions); dipolar molecules or ions possessing simultaneously a positive and a negative electric charge at different structural points of the same molecular structure, behaving as an ionic hybrid.
• Aminone — A generic name rarely used to describe a cyclic organic molecular structure or an unsaturated ketone structurally modified by grafting an amino group. This isolated technical term is encountered in laboratory jargon for classifying certain synthesis intermediates used in preparing dyes or pharmaceutical compounds.
• Aminated — Having undergone the process of amination or structurally modified by introducing an amino group; an organic compound, polymer, or carbohydrate grafted with reactive nitrogenous functions, frequently used in applied biochemistry to modify surface properties.
• Anabazin — A non-literary or obsolete orthographic variant for the feminine noun 'anabasină' (anabasine). It designates the toxic liquid alkaloid isolated from certain plants, with pharmacological properties analogous to nicotine, used industrially in formulating powerful insecticides or in laboratory studies on neuroreceptors.
• Anisomer — An asymmetric isomer or a compound substance formed by molecules whose segments or atomic groups do not present an equal ratio of geometric, structural, or molecular mass symmetry. As an adjective, it describes a state, chemical bond, or macromolecular process characterized by the inequality of components or polymeric segments, causing divergent physico-chemical properties.
• Antimonyl — A monovalent chemical radical composed of one antimony atom and one oxygen atom (SbO), wherein stibium acts in a trivalent valence state; a functional group that structurally enters the composition of certain complex salts, such as antimony potassium tartrate (tartar emetic). In an industrial and pharmaceutical sense, its compounds were historically used as emetics or mordanți in dyeing.
• Anthic substance — An organic substance, plant pigment, or chemical derivative extracted from or structurally correlated with plants of the genus Anthus or specific floral elements; it may also describe a morphological feature or microscopic structural composition presenting affinities with flower biology. In a biochemical sense, it defines a natural compound used in the laboratory for its reactive or spectral coloring properties.
• Arene — A generic name assigned to aromatic hydrocarbons, cyclo-unsaturated organic compounds containing at least one stable benzene nucleus or ring within their molecular structure. In a structural sense, arenes feature a completely delocalized pi-pi electronic conjugation, responsible for their exceptional chemical stability, specific electrophilic substitution properties, and pronounced aromatic character.
• Arylated — Having undergone the process of arylation; an organic compound or molecule into whose structure one or more aryl groups have been successfully introduced. In a technical sense, it describes the final state of a chemical product structurally modified by attaching a stable aromatic radical.
• Arsenobenzene — An organic cyclic chemical compound containing a double bond between two arsenic atoms attached to phenyl groups, with the basic chemical formula C6H5As=AsC6H5. Its structural derivatives held a crucial historical importance in 20th-century medicine, forming the basis of the first effective synthetic antimicrobial treatments, such as Salvarsan used against syphilis.