[en] An investigation of the cause of the higher (by a factor of approx.1.5) yields of trapped electrons [G (e^-/sub t/)] produced by the γ irradiation of 3-methylpentane-d₁₄ (3MP-d₁₄), methylcyclohexane-d₁₄ (MCHx-d₁₄), and 3-methylheptane-d₁₈ (3MHp-d₁₈) glasses at 77 K as compared to 3MP-h₁₄, MCHx-h₁₄, and 3MHp-h₁₈ has provided new evidence and insight on such isotope effects and on the effects of molecular structure on G (e^-/sub t/). The absolute reduction in G (e^-/sub t/) by a given concentration of the electron scavengers SF₆, CH₃I, and biphenyl (phi₂) is always greater in the deuterated than in the protiated form of 3MP or MCHx. G (phi^-₂) from the scavenging of e^- by phi₂ is higher in 3MP-d₁₄ than 3MP-h₁₄, in MCHx-d₁₄ than in MCHx-h₁₄ and in either form of 3MP than MCHx. The fractional decay rate of e^-/sub t/ is slower in deuterated than protiated matrices both at the glass transition temperature and below, and is faster than the fractional decay rate of trapped radicals. The decay rates are reduced by positive charge scavengers. G (TMPD⁺) from the scavenging of positive charge by tetramethylparaphenylenediamine (TMPD) is the same, independent of deuteration, in 3MP-d₁₄ and in 3MP-h₁₄ glasses and varies with molecular structure. The positive charge scavengers 2-methyl-1-pentene (2MP-1), triethylamine (TEA), and propene (C₃H₆ and C₃D₆) each cause an equal or greater absolute increase in G (e^-/sub t/) in perdeuterated than in the corresponding protiated matrices. They give different profiles of enhancement vs concentration in different alkanes. C₃H₆ and C₃D₆ produce different G (3^-/sub t/) enhancement profiles when compared in the same matrix. The optical spectra of e^-/sub t/ in deuterated and protiated alkanes and alkanes of different molecular structure are similar