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Synthesis, Structure, and Decomposition of (NH 4 ) 2 [Mo 6 Cl 14 ] · H 2 O
Author(s) -
Nägele Andreas,
Gibson Katharina,
Lachgar Abdessadek,
Meyer H.Jürgen
Publication year - 1999
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/(sici)1521-3749(199905)625:5<799::aid-zaac799>3.0.co;2-m
Subject(s) - monoclinic crystal system , chemistry , crystallography , thermal decomposition , crystal structure , decomposition , aqueous solution , yield (engineering) , materials science , organic chemistry , metallurgy
(NH 4 ) 2 [Mo 6 Cl 14 ] · H 2 O ( 1 ) was prepared from reactions of MoCl 2 in ethanol with aqueous NH 4 Cl solution. It crystallizes in the monoclinic space group I2/a (no. 15), Z = 4 with a = 912.3(1), b = 1491.2(2), c = 1724.8(2) pm, β = 92.25(1)°; R1 = 0.023 (based on F values) and wR2 = 0.059 (based on F 2 values), for all measured X‐ray reflections. The structure of the cluster anion can be given as [(Mo 6 Cl i 8 )Cl a 6 ] 2– (i = inner, a = outer ligands). Thermal stability studies show that 1 loses crystal water followed by the loss of NH 4 Cl above 350 °C to yield MoCl 2 . The water‐free compound (NH 4 ) 2 [Mo 6 Cl 14 ] ( 2 ) was synthesized by solid state reaction of MoCl 2 and NH 4 Cl in a sealed quartz ampoule at 270 °C. No single‐crystals could be obtained. Decompositions of 1 and 2 under nitrogen and argon exhibited the loss of NH 4 Cl at about 350 °C. Decomposition under NH 3 resulted in the formation of MoN and Mo 2 N at 540 °C and 720 °C, respectively.