Amino Acids under Hydrothermal Conditions: Apparent Molar Volumes of Aqueous α-Alanine, β-Alanine, and Proline at Temperatures from 298 to 523 K and Pressures up to 20.0 MPa
Amino Acids under Hydrothermal Conditions: Apparent Molar Volumes of Aqueous α-Alanine, β-Alanine, and Proline at Temperatures from 298 to 523 K and Pressures up to 20.0 MPa
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DOI：
10.1021/jp984791r
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发表时间：
1999-05
影响因子：
3.3
通讯作者：
Rodney G. Clarke and;P. Tremaine
中科院分区：
文献类型：
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作者：
Rodney G. Clarke and;P. Tremaine
用铂振管密度计测定了在298K~523K温度和超过蒸汽饱和的压力下，α-丙氨酸、β-丙氨酸和Pro的表观摩尔体积V。氨基酸水溶液的标准偏摩尔体积V°随温度升高而增大，然后在398K以上偏向负值，这与溶液中相对于水的临界温度的降低相一致。这与Shock和Helgeson(Geochim)建立的关联式所预测的行为相反。宇宙人。行动。1990年54年，915年−945)和修正和赫尔格森(J.化学。作者：Faraday Trans.1997年93、1927年−1941年)。随着Tc的接近，两性离子的大偶极矩对溶剂极化对V°的贡献偏离负无穷大，其方式类似于每种氨基酸的水溶液的V°值。虽然这一协议在质量上是一致的，但在数量上并不一致，这表明……
The apparent molar volumes Vφ of aqueous α-alanine, β-alanine, and proline have been determined with platinum vibrating tube densitometers at temperatures from 298 to 523 K and at pressures in excess of steam saturation. Values of the standard partial molar volumes V° for the aqueous amino acids increase with temperature then deviate toward negative values at temperatures above 398 K, consistent with a lowering of the critical temperature in the solutions relative to water. This is opposite to the behavior predicted by the correlations developed by Shock and Helgeson (Geochim. Cosmochim. Acta. 1990 54, 915−945) and Amend and Helgeson (J. Chem. Soc., Faraday Trans. 1997 93, 1927−1941). The contribution to V° from the solvent polarization by the large dipole moment of the zwitterions deviates toward negative infinity as Tc is approached, in a manner similar to the V° values for each of the aqueous amino acids. While this agreement is qualitatively consistent, it is not quantitatively consistent, which sugge...