From Lead(II) Dithiocarbamate Precursors to a Fast Response PbS Positive Temperature Coefficient Thermistor

Abstract

PbS submicron crystals were formed by thermolysis of two different lead dithiocarbamate complexes. These precursors were readily synthesized and fully characterized, and in situ synchrotron powder diffraction experiments were performed to characterize their decomposition. The structure and purity of resultant PbS was examined using scanning electron and transmission electron microscopies, powder X-ray diffraction, and infrared spectroscopy. Submicron crystalline PbS was used to create a new PbS thermistor with excellent sensitivity and an ultrarapid thermal response time.

An Unusual Mercury(II) Diisopropyldithiocarbamate Coordination Polymer

“…There is one intramolecular C-H···S hydrogen bond of ~ 2.4 Å between S1 and H2, creating an electronic Cl N asymmetry about the two isopropyl groups within each ligand, in agreement with previous reports. [9][10][11] All ligand bond lengths are similar to those in other DIPDTC complexes. 9-11, 48, 51-55 The structure of polymeric 2 contains a bonding motif that is new for mercury dithiocarbamate complexes 1 .…”

“…In the spectrum of 1, a single set of peaks corresponding to each of the carbon atoms indicates equivalent DIPDTC moieties. As with other DIPDTC complexes, 9,57 the non-equivalence of the isopropyl environments (due to intramolecular C-H···S hydrogen bonding) 11 gives rise to two separate methine carbon signals at δc 51.7 and 61.8 ppm. The dithiocarbamato carbon signal appears at δc 200.8 ppm and has a slightly higher chemical shift than the corresponding signal in the spectrum of Pb(DIPDTC)2 9 , likely arising from differential contributions from the Pb and Hg bonding orbitals.…”

“…Spectra obtained using a mixture of 1 and 2 (determined using solid-state 199 Hg NMR spectroscopy) contained a single set of signals that remained indistinguishable even at lower temperatures (238 K). In addition, DOSY-NMR at room temperature ( Figure S2) revealed a single set of signals with a single revealed kinetic insights on the restricted rotation of the isopropyl groups (due to intramolecular C-H·· S interactions and steric effects) 9,11 Examination of the variable-temperature experimental data yielded an energy barrier (ΔG ‡ ) to free rotation at coalescence (268 K) of 59 kJ mol -1 , which is in excellent agreement with our previously reported data for NaDIPDTC (56 kJ mol -1 ) 11 and PbDIPDTC (57 kJ mol -1 ) 9 , indicating an equivalent transition state during isopropyl bond rotation (despite the fact that experiments were performed in different solvents). The values for ΔH ‡ (37 kJ mol -1 ), ΔS (-75 J mol -1 K -1 ) and an activation energy of 40 kJ mol -1 are somewhat similar to those for NaDIPDTC and PbDIPDTC indicating comparable degrees of C-H···S and steric interactions.…”

“…Thus, metal dithiocarbamate complexes have been extensively studied in the area of crystal growth and design and as single source precursors for metal sulfide crystal synthesis. 1,4,7,9,[17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] Of particular relevance to the current work, mercury (II) dithiocarbamate complexes produce a diverse range of molecular architectures and isomers; generating at least five distinct structural motifs in systems bearing two dithiocarbamate ligands. 1 The reaction of HgCl2 with diethyldithiocarbamate has been reported to produce three unique crystals (two polymorphs and an isomer) during crystal growth.…”

Synthesis, Crystal Structure, and Selected Properties of [Au(S2CNH2)2]SCN: A Precursor for Gold Macro‐Needles Consisting of Gold Nanoparticles Glued by Graphitic Carbon Nitride

“…[7,8] These compounds are also used for the removalo ft ransition metalc ations from different fluid media. [9][10][11] In the last few years, dithiocarbamate complexes have been applied as single-sourcep recursors for the preparation of metal sulfides by thermald ecomposition [12][13][14][15][16] or for the generation of sulfide films. [17][18][19][20] The first Au I dithiocarbamatec ompounds were reported by Akerstrçm (1959 [21] ), and after this publicationt he chemistry of such compounds was developedr apidly.…”