On Plenary Train Algebras of Rank 4

The existence of idempotent elements in plenary train algebras of rank greater than 3, is an open problem to be solved. J. Carlos Gutierrez's results on plenary train algebras in Gutierrez (2000 Gutierrez , J. C. ( 2000 ). Principal and plenary train algebras . Comm. Algebra 28 ( 2 ): 653 – 667 . [Google Scholar]) are based on the underlying assumption of the existence of an idempotent. In this article we study conditions on the scalars defining a plenary train algebra of rank 4 to assure the existence of such an idempotent.     

Stable doubly charged positive molecular ions formed by direct attachment of alpha particles to HCN and HNC

The existence of [HeNCH](2+) and [HeCNH](2+) is examined by reliable high-level ab initio methods. It is shown that both species are metastable with respect to the proton loss process, but the activation barriers are high enough to accommodate several resonant states. Their estimated lifetimes are practically infinite for v<3, implying that the attachment of alpha particles to HNC and HCN yields kinetically stable dications. This could be an important factor in the cyanide chemistry in interstellar and comet environments.     

Cu2+ ion-sensitive surface on graphite electrodes

Analytical and Bioanalytical Chemistry - A new electrochemical interface based on polyacrylic acid (PAAcid) immobilized in a Nafion® polymeric matrix on graphite screen-printed electrodes for...     

One-pot synthesis of α-amino phosphonates from α-amino acids and β-amino alcohols

The one-pot radical fragmentation-phosphorylation reaction of α-amino acids and β-amino alcohols affords α-amino phosphonates in good yields. The reaction was applied to the synthesis of potentially bioactive phosphonates.     

Bivariate hypergeometric D-modules

We undertake the study of bivariate Horn systems for generic parameters. We prove that these hypergeometric systems are holonomic, and we provide an explicit formula for their holonomic rank as well as bases of their spaces of complex holomorphic solutions. We also obtain analogous results for the generalized hypergeometric systems arising from lattices of any rank.     

Molecular magnetism in closo-azadodecaborane supericosahedrons

ABSTRACT

The connection of 12 s = ½ closo-azadodecaborane radical units (NB₁₁H₁₁?), where a hydrogen atom is removed from the nitrogen atom, produces a supericosahedron [(NB₁₁H₆?)₁₂]^(S), S being the total spin of the system. This work describes the study of the low-lying energy spin-projected states of this supericosahedron with two different geometrical arrangements, each nitrogen atom pointing (1) inwards or (2) outwards with respect to radial axes. These spin-projected states are mapped into a Heisenberg spin Hamiltonian, thus allowing the determination of coupling constants between magnetic sites. The eigenvalues of this model Hamiltonian then predict the ground spin state and the corresponding combinations of spin orientations of the magnetic centres. We show that the energy minimum in the [(N_in/outB₁₁H₆?)₁₂]^(S) systems corresponds to a high-spin S = 6 state.