Studies in rare isopoly molybdates

On Bonding, Structure, and Stability of Ternary Hydrides A2MH2 (A = Li, Na; M = Pd, Pt)

“…Since hydrogen has no p-acceptor orbitals, r-donation from H ± to M 0 cannot be promoted by p-backdonation, which is the common mechanism to stabilize low formal oxidation numbers of metal atoms. The mixing of M±(n + 1) s and A±n'sp into the M±nd/H±1 s valence band has been noted in this context [7,8,9]. According to those approximate band structure calculations, the weak indirect overlap of the highest valence band with the alkali metal conduction band is responsible for the metallic lustre and conductivity, but it can only weakly contribute to bonding, i. e. does not corroborate the respective speculations of Ref.…”

Chemical bonding features of the ternary alkali metal platinum and palladium hydrides

“…In the interstitial region, a suitable mean of the electronic density charge tails is performed yielding a constant potential. The form of the LDA used was the Slater X α which has been proved to be adequate to study this kind of material [11,12], and the self-consistency effect, not included in the present work, has been shown to result in very minor differences in the palladium system K 2 PdH 4 [18,19]. Like in our previous calculation and although Pd and Pt are heavier atoms, we used a nonrelativistic Hamiltonian [18,19].…”

“…The electronic structure of K 2 PdH 4 has recently been investigated by means of the linear muffin-tin orbitals method in the atomic sphere approximation [18,27] and is very similar to that of Na 2 PdH 4 since the two hydrides have the same crystal structure. However, in K 2 PdH 4 the band widths are systematically narrower than in Na 2 PdH 4 owing to the larger T-T distances in the former.…”

Amperometric titrations

“…T h e amperometric titration of zirconium in 0.1M KC1-0.01% gelatin with NayMoOa has been carried out a t a D M E potential of -1.7 volt (83). Suprunovich and Usatenko (289) have studied the R P E titration of molybdate with 8-mercaptoquinoline.…”

“…Methods Involving Molybdenum and Tungsten Species. The amperometric titration of zirconium in 0.1 M KC1-0.01% gelatin with Na2Mo04 has been carried out at a DME potential of -1.7 volt (83). Suprunovich and Usatenko Successive titrations, such as of iron, copper, and molybdenum, were demonstrated and the principle was used to determine iron and molybdenum in chrome-nickel steel.…”