Technical barriers to a hydrogen economy adoption are not as significant as one might think as key technologies in the hydrogen network are already mature with working prototypes already developed for technologies such as liquid hydrogen composite cryotanks and proton exchange membrane fuel cells. At present high technology costs still are a barrier to widespread hydrogen adoption but it is envisioned that as scale of production increases, then costs are likely to fall.
In this paper a review is undertaken to identify the current state of development of key areas of the hydrogen network such as production, distribution, storage and power conversion technology. However, there are practical limitations to its widespread use at present which include low volumetric energy density in the gaseous state and high well-to-wheel costs when compared to fossil fuel production and distribution.
In addition to zero CO 2 emissions, hydrogen has several other attractive properties such as higher gravimetric energy content and wider flammability limits than most fossil fuels. In comparison to fossil fuel use the burning of hydrogen results in zero CO 2 emissions and it can be obtained from renewable energy sources. Single-crystal X-ray analyses ofNi(L)2 and 2 complexeswere also carried out to prove the molecular topologies.To meet ambitious targets for greenhouse gas emissions reduction in the 2035-2050 timeframe, hydrogen has been identified as a clean “green” fuel of interest. The magnetic susceptibilities of the complexeswere measured to confirm the hybridization patterns and the geometries. The compounds were characterized by elemental analysis MS, FTIR, and Raman spectroscopies. Similar to many other nickel(II) complexes, the Ni(L)2 reacts reversibly with pyridine to yield the octahedral complex (). The coordination geometry was square planar in the nickel(II) complex and tetrahedral in the others. The complexes were all of the stoichiometry of x, with x = 1 for M = Ni2+ and x = 2 for M = Co2+, Cd2+ and Zn2+. HL was obtained through the addition reaction of the perthiophosphonic acid anhydride Lawesson reagent, (LR),, with the corresponding Grignard compound (benzylmagnesium bromide) in diethyl ether medium. The nickel complex was further treated with pyridine which led to the formation of octahedral dipyridine derivative. X-ray studies confirmed the nonplanar, fourcoordination geometry of the complexes and indicate that electron delocalization prevails in the PS−2 moiety of the dithiophosphinato groups.īenzyl(4-methoxyphenyl)dithiophosphinic acid (HL) was obtained as solid and was treated with the NiCl26H2O, CoCl26H2O, ZnCl2, and CdCl2 to prepare its Ni(II), Co(II), Zn(II), and Cd(II) complexes. The crystal structures of 2 and 2 were also studied as examples. The structures of the complexes were elucidated by elemental analysis, MS, FTIR and Raman spectroscopy techniques as well as 1H-, 13C- and 31P- NMR. These salts were treated with CdCl2 in ethanol at room temperature to produce the bis-dithiophosphinato cadmium complexes (2) exclusively. The acids formed were transformed into easily crystallizable ammonium salts (NH4L) for purification.
The acid forms of the ligands were obtained by treatment of the Lawesson reagent, (LR) with the corresponding Grignard reagent in dry diethylether. To the best of our knowledge, this is the first report on the preparation and characterization of the n-butylderivative. The five dithiophosphinato ligands (L) involved were of the general structure H3CO-C6H4-(R)PS−2 with R= 3-methylbutyl, (L1) n-butyl, (L2) 2-methylpropyl, (元) 1-methylpropyl, (L4) and 2-propyl, (L5). New cadmium complexes of 4-methoxyphenyl dithiophosphinic acids, H3CO-C6H4-(R)PS2Hwere prepared.
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