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考虑到影响R_1CH_2_nR_2的气相标准生成焓△_fH_m~(R_1CH_2_nR_2,g)的各种因素,包括端基,链因子(n)及主链上取代基的支化度等。提出了计算正、异构烷烃(RCH_2_nR)的△_fH_m~(g)的计算模型: △_fH_m~(R_1CH_2_nR_2,g)=-74.4kJ·mol~(-1)-4.9T-20.5n+∑m_ib_i其中:-74.4kJ·mol~(-1)为CH_4的△_fH_m~(g),-4.9为主链上端基(-CH_3)对△_fH_m~(R_1CH_2_nR_2)的贡献,T为端基的数目,n为组成上与CH_2相当的-CH_2-的数目,-20.5为其对△_fH_m~(R_1CH_2_nR_2,g)的贡献,b_i为每类取代基的支化度,m_i为b_i的数目。本文的计算值与实验值很好吻合,相关系数为0.9997。
Considering various factors that influence the gas phase standard enthalpy of formation, Δ_fH_m ~ (R_1CH_2_nR_2, g), including the terminal groups, the chain factor (n) and the degree of branching of the substituents on the main chain, etc. A computational model for calculating △ _fH_m ~ (g) of normal and isoparaffinic hydrocarbons (RCH_2_nR) is proposed: △ _fH_m ~ (R_1CH_2_nR_2, g) = -74.4kJ · mol -1 (-1) -4.9T-20.5n + Σm_ib_i : -74.4kJ · mol -1 △ _fH_m ~ (g) of CH_4, 4.9 is the contribution of the main chain end group (-CH_3) to △ _fH_m ~ (R_1CH_2_nR_2), T is the number of end groups, n Is the number of -CH 2 - corresponding to CH 2 on the composition, -20.5 is its contribution to △ _fH_m ~ (R_1CH_2_nR_2, g), b_i is the degree of branching of each type of substituent, and m_i is the number of b_i. The calculated values agree well with the experimental ones, and the correlation coefficient is 0.9997.