GLOSSARY Benzylic carbon (Section 11.10): A carbon directly attached to Baeyer strain theory (Section 3.4): Incorrect nineteenth-cen a benzene ring. a hydrogen attached to a benzylic carbon is tury theory that considered the rings of cycloalkanes to be a benzylic hydrogen. A carbocation in which the benzylic planar and assessed their stabilities according to how much carbon is positively charged is a benzylic carbocation. A the angles of a corresponding regular polygon deviated free radical in which the benzy lic carbon bears the unpaired from the tetrahedral value of 109,5o lectron is a benzylic radical. aeyer-illiger oxidation( Section 17.16): Oxidation of an Benzyne(Section 23.8): The compound hyde or, more commonly, a ketone with a peroxy acid The product of Baeyer-Villiger oxidation of a ketone is an ester RCR Ball-and-stick model(Section 1.10): Type of molecular model n which balls representing atoms are connected by sticks Benzyne is formed as a reactive representing bonds. Similar to ball-and-spoke models of of aryl halides with very stror Learning By Modeling Base(Section 4.6): According to the Arrhenius definition, Bile acids (Section 26.13): Steroid derivatives biosynthesized ubstance that ionizes in water to produce hydroxide ions the liver that aid digestion by emulsifying fats. According to the Bronsted-towry definition, a substance Bimolecular (Section 4.7): A process in which two particles re- that accepts a proton from some suitable donor. According act in the same elementary ster to the Lewis definition, an electron-pair donor. Biological isoprene unit (Section 26.8): Isopentenyl pyrophos- Base pair(Section 27. 27): Term given to the purine of a nu phate, the biological precursor to terpenes and steroids: cleotide and its complementary pyrimidine Adenine(A)is omplementary to thymine(T), and guanine(G)is comple entary to cytosine( C). Base peak (Section 13.21): The most intense peak in a mass spectrum. The base peak is assigned a relative intensity of Birch reduction(Section 11.11): Reduction of an aromatic ring 100, and the intensities of all other peaks are cited as a per- to a 1, 4-cyclohexadiene on treatment with a group I metal entage of the base (i, Na, K)and an alcohol in liquid ammonia. Basicity constant Kb(Section 22. 4):A measure of bas Boat conformation (Section 3.5): An unstable conform cyclohexane, depicted a Kb=IRyNH*HO-I IRa Bending vibration(Section 13. 19): The regular, repetitive mo- tion of an atom or a group along an arc the radius of whic is the bond connecting the atom or group to the rest of the T bond ( Section 1. 17): In alkenes, a bond formed by overlap of type of molecular orbitals in a side-by-side manner. A T bond is weaker than motion that gives rise to a peak in the infrared spectrum. a o bond. The carbon -earbon double bond in alkenes con- Benedict's reagent (Section 25. 19): A solution containing the ists of two sp-hybridized carbons joined by a g bond and citrate complex of CuSO4. It is used to test for the presence of reducing sugars o bond (Section 1.14): A connection between two atoms in Benzene(Section 11. 1): The most typical aromatic hydrocar hich the electron probability distribution has rotational symmetry along the internuclear axis. A cross section per- pendicular to the internuclear axis is a circle Bond dissociation energy (Section 1.3): For a substance A: B, the energy required to break the bond between A and b so that each retains one of the electrons in the bond table 4.3 (Section 4.17)gives bond dissociation energies for some representative compounds Bonding orbital(Section 1. 14): An orbital in a molecule in which an electron is more stable than when localized on an Benzyl group (Section 11.7): The group C6HSCH isolated atom. All the bonding orbitals are normally doubl occupied in stable neutral molecules Forward Main Menu TOC Study Guide Toc Student OLCMHHE WebsiteGLOSSARY G-4 Baeyer strain theory (Section 3.4): Incorrect nineteenth-cen￾tury theory that considered the rings of cycloalkanes to be planar and assessed their stabilities according to how much the angles of a corresponding regular polygon deviated from the tetrahedral value of 109.5°. Baeyer—Villiger oxidation (Section 17.16): Oxidation of an aldehyde or, more commonly, a ketone with a peroxy acid. The product of Baeyer—Villiger oxidation of a ketone is an ester. Ball-and-stick model (Section 1.10): Type of molecular model in which balls representing atoms are connected by sticks representing bonds. Similar to ball-and-spoke models of Learning By Modeling. Base (Section 4.6): According to the Arrhenius definition, a substance that ionizes in water to produce hydroxide ions. According to the Brønsted—Lowry definition, a substance that accepts a proton from some suitable donor. According to the Lewis definition, an electron-pair donor. Base pair (Section 27.27): Term given to the purine of a nu￾cleotide and its complementary pyrimidine. Adenine (A) is complementary to thymine (T), and guanine (G) is comple￾mentary to cytosine (C). Base peak (Section 13.21): The most intense peak in a mass spectrum. The base peak is assigned a relative intensity of 100, and the intensities of all other peaks are cited as a per￾centage of the base peak. Basicity constant Kb (Section 22.4): A measure of base strength, especially of amines. Kb Bending vibration (Section 13.19): The regular, repetitive mo￾tion of an atom or a group along an arc the radius of which is the bond connecting the atom or group to the rest of the molecule. Bending vibrations are one type of molecular motion that gives rise to a peak in the infrared spectrum. Benedict’s reagent (Section 25.19): A solution containing the citrate complex of CuSO4. It is used to test for the presence of reducing sugars. Benzene (Section 11.1): The most typical aromatic hydrocar￾bon: Benzyl group (Section 11.7): The group C6H5CH2±. H H H H H H [R3NH][HO] [R3N] RCR O X RCOR O X RCOOH O X Benzylic carbon (Section 11.10): A carbon directly attached to a benzene ring. A hydrogen attached to a benzylic carbon is a benzylic hydrogen. A carbocation in which the benzylic carbon is positively charged is a benzylic carbocation. A free radical in which the benzylic carbon bears the unpaired electron is a benzylic radical. Benzyne (Section 23.8): The compound Benzyne is formed as a reactive intermediate in the reaction of aryl halides with very strong bases such as potassium amide. Bile acids (Section 26.13): Steroid derivatives biosynthesized in the liver that aid digestion by emulsifying fats. Bimolecular (Section 4.7): A process in which two particles re￾act in the same elementary step. Biological isoprene unit (Section 26.8): Isopentenyl pyrophos￾phate, the biological precursor to terpenes and steroids: Birch reduction (Section 11.11): Reduction of an aromatic ring to a 1,4-cyclohexadiene on treatment with a group I metal (Li, Na, K) and an alcohol in liquid ammonia. Boat conformation (Section 3.5): An unstable conformation of cyclohexane, depicted as bond (Section 1.17): In alkenes, a bond formed by overlap of p orbitals in a side-by-side manner. A bond is weaker than a  bond. The carbon—carbon double bond in alkenes con￾sists of two sp2 -hybridized carbons joined by a  bond and a bond.  bond (Section 1.14): A connection between two atoms in which the electron probability distribution has rotational symmetry along the internuclear axis. A cross section per￾pendicular to the internuclear axis is a circle. Bond dissociation energy (Section 1.3): For a substance A:B, the energy required to break the bond between A and B so that each retains one of the electrons in the bond. Table 4.3 (Section 4.17) gives bond dissociation energies for some representative compounds. Bonding orbital (Section 1.14): An orbital in a molecule in which an electron is more stable than when localized on an isolated atom. All the bonding orbitals are normally doubly occupied in stable neutral molecules. OPP H H H H