105833-70-3Relevant articles and documents
The solventless syntheses of unique PbS nanowires of X-shaped cross sections and the cooperative effects of ethylenediamine and a second salt
Chen, Jing,Chen, Ling,Wu, Li-Ming
, p. 8038 - 8043 (2007)
Unique PbS nanowires with x-shaped cross sections, with diameters in the range of 300-800 nm with an average of 598 nm (σ = ±21.7%), and lengths of up to several tens of micrometers, have been made by a solventless method. Such nanowires show high adsorptivities of the PbS nanooctahedra, which can be washed off by ultrasound. The suitable precursor is obtained from a Pb(NO3)2/octanoate/ethylenediamine/dodecanethiol molar ratio of 1:2:1:1.6, and the PbS nanowires are produced by the thermolysis of such precursors at 280°C for 1 hour. The X-ray diffraction, scanning electron microscopy, and transmission electron microscopy characterizations of the products and the keys of the morphological control have been reported. For the formation of such products, two cooperative effects are found to be crucial, the roles of ethylenediamine and a second salt, lead octanonate.
Lead(ii) soaps: Crystal structures, polymorphism, and solid and liquid mesophases
Martínez-Casado,Ramos-Riesco,Rodríguez-Cheda,Redondo-Yélamos,Garrido,Fernández-Martínez,García-Barriocanal,Da Silva,Durán-Olivencia,Poulain
, p. 17009 - 17018 (2017/07/24)
The long-chain members of the lead(ii) alkanoate series or soaps, from octanoate to octadecanoate, have been thoroughly characterized by means of XRD, PDF analysis, DSC, FTIR, ssNMR and other techniques, in all their phases and mesophases. The crystal structures at room temperature of all of the members of the series are now solved, showing the existence of two polymorphic forms in the room temperature crystal phase, different to short and long-chain members. Only nonanoate and decanoate present both forms, and this polymorphism is proven to be monotropic. At higher temperature, these compounds present a solid mesophase, defined as rotator, a liquid crystal phase and a liquid phase, all of which have a similar local arrangement. Since some lead(ii) soaps appear as degradation compounds in oil paintings, the solved crystal structures of lead(ii) soaps can now be used as fingerprints for their detection using X-ray diffraction. Pair distribution function analysis on these compounds is very similar in the same phases and mesophases for the different members, showing the same short range order. This observation suggests that this technique could also be used in the detection of these compounds in disordered phases or in the initial stages of formation in paintings.
Coordination geometry of lead carboxylates - Spectroscopic and crystallographic evidence
Catalano, Jaclyn,Murphy, Anna,Yao, Yao,Yap, Glenn P. A.,Zumbulyadis, Nicholas,Centeno, Silvia A.,Dybowski, Cecil
, p. 2340 - 2347 (2015/01/30)
Despite their versatility, only a few single-crystal X-ray structures of lead carboxylates exist, due to difficulties with solubility. In particular, the structures of long-chain metal carboxylates have not been reported. The lone electron pair in Pb(ii) can be stereochemically active or inactive, leading to two types of coordination geometries commonly referred to as hemidirected and holodirected structures, respectively. We report 13C and 207Pb solid-state NMR and infrared spectra for a series of lead carboxylates, ranging from lead hexanoate (C6) to lead hexadecanoate (C18). The lead carboxylates based on consistent NMR parameters can be divided in two groups, shorter-chain (C6, C7, and C8) and longer-chain (C9, C10, C11, C12, C14, C16, and C18) carboxylates. This dichotomy suggests two modes of packing in these solids, one for the short-chain lead carboxylates and one for long-chain lead carboxylates. The consistency of the 13C and 207Pb NMR parameters, as well as the IR data, in each group suggests that each motif represents a structure characteristic of each subgroup. We also report the single-crystal X-ray diffraction structure of lead nonanoate (C9), the first single-crystal structure to have been reported for the longer-chain subgroup. Taken together the evidence suggests that the coordination geometry of C6-C8 lead carboxylates is hemidirected, and that of C9-C14, C16 and C18 lead carboxylates is holodirected.
Phase diagrams and optical properties of binary liquid-crystal systems of cobalt(II) caprylate with a divalent metal caprylate
Tokmenko,Mirnaya,Yaremchuk
, p. 1141 - 1145 (2012/10/08)
Phase equilibria in the binary systems of cobalt(II) caprylate with a divalent metal (lead, cad- mium, or zinc) caprylate were studied by differential thermal analysis and polarization microscopy, and the concentration and temperature ranges of the existence of liquid crystals and glasses were determined. Con- tinuous or boundary smectic liquid-crystal solutions were found to form in all the systems. The temperature and concentration dependences of the electronic absorption spectra of liquid crystals and glasses in binary systems based on cobalt caprylate were investigated. Pleiades Publishing, Ltd., 2012.
