Martínez Casado F J, Ramos Riesco M, Sánchez Arenas A, García Pérez M V, Redondo M I, López-Andrés S, Garrido P L, Cheda J A R
Departamento de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain.
J Phys Chem B. 2008 Dec 25;112(51):16601-9. doi: 10.1021/jp804757n.
Lead(II) pentanoate was studied by DSC, XRD, and FTIR and solid state CP/MAS-NMR spectroscopies. A transition from the crystal to the intermediate phase, at T(ss) = 328.2 +/- 0.6 K, with delta(ss)H = 8.8 +/- 0.1 kJ x mol(-1), and a melting at T(f) = 355.6 +/- 0.3 K, with delta(f)H = 12.6 +/- 0.1 kJ x mol(-1), were observed on first heating. The thermal and structural behavior of the lead(II) pentanoate shows as a link between those of the shorter and longer members of the previously studied lead(II) alkanoate series. The optical microscopy and FTIR vs temperature studies show structural changes from the crystal to the intermediate phase and its solid state nature. Moreover, X-ray diffraction and C-13 and Pb-207 CP/MAS-NMR studies confirm the rotator nature of the intermediate phase in this compound. Two different glass states, one from the isotropic liquid and another from the rotator phase, were obtained by quenching at high and low rates, respectively. The glass transition temperatures (measured at 5 K x min(-1)) were 322.9 and 275.7K, respectively.
通过差示扫描量热法（DSC）、X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）以及固态交叉极化/魔角旋转核磁共振（CP/MAS-NMR）光谱对戊酸铅（II）进行了研究。在第一次加热时，观察到在T(ss) = 328.2 ± 0.6 K时从晶体到中间相的转变，Δ(ss)H = 8.8 ± 0.1 kJ·mol⁻¹，以及在T(f) = 355.6 ± 0.3 K时的熔化，Δ(f)H = 12.6 ± 0.1 kJ·mol⁻¹。戊酸铅（II）的热行为和结构行为显示出它是先前研究的链烷酸铅（II）系列中较短和较长成员之间的一种联系。光学显微镜以及FTIR随温度变化的研究表明了从晶体到中间相的结构变化及其固态性质。此外，X射线衍射以及碳-13和铅-207的CP/MAS-NMR研究证实了该化合物中间相的旋转体性质。通过分别以高速率和低速率淬火，获得了两种不同的玻璃态，一种来自各向同性液体，另一种来自旋转体相。玻璃化转变温度（在5 K·min⁻¹下测量）分别为322.9 K和275.7 K。
