A new mixed group 5 metal selenide, Nb(1.41)V(0.59)Se(9).

ABSTRACT: The new mixed-metallic phase, niobium vanadium nona-selenide, (Nb(2-x)V(x))Se(9) (0.18? x ? 0.59) is isostructural with monoclinic V(2)Se(9). The structure is composed of chains of bicapped trigonal-prismatic [MSe(8)] units. The metal (M) site is occupied by statistically disordered Nb [0.706?(5)] and V [0.294?(5)] atoms. Two trigonal prisms are linked by sharing a recta-ngular face composed of two Se(2) (2-) pairs. Through three edging and capping Se atoms, the chains are extended along [101]. The chain shows alternating short [2.8847?(7)?Å] and long [3.7159?(7)?Å] M-M distances. The structure shows a wide range of Se-Se inter-actions. In addition to the Se(2) (2-) pairs of the recta-ngular face, an inter-mediate Se?Se separation [2.6584?(5)?Å] is found. The amount of each metal can vary, [(Nb(2-x)V(x))Se(9), 0.18 ? x ?m 0.59] and they seem to form a random substitutional solid solution. The M-M distances increase gradually by increasing the amount of Nb atoms. The classical charge-balance of the compound can be described as [M(4+)](2)[Se(2) (2-)](2)[Se(5) (4-)].

SUBMITTER: Lee E 

PROVIDER: S-EPMC3200691 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature