ISSN:
1572-901X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary Three isostructural compounds of general formula (3-MepyH) x (3-EtpyH)4−x [Mo8O26] (x=0, 2, 4) crystallize in the monoclinic system, space group P21/n, Z=2. Previously determined parameters for the compoundx=4 area=13.652(2),b=10.887(1),c=13.759(1) Å, β=90.87(1)°,V=2044.8(4) Å3,Dx=2.53,Do=2.54(1) mg m−3,F(000)=1496. Slight differences in cell dimensions have been observed whenx=0 or 2. A nonisomorphous compound of formula (3-MepyH)3(3-EtpyH)[Mo8O26]·H2O crystallizes in the triclinic system, space group P21/n,Z=2,a=10.918(1),b=10.985(3),c=18.991(2) Å, α=97.19(2), β=91.45(2), γ=107.30(2)0,V=2152.8(7) Å3,Dx=2.456,Do=2.456(5) mg m−3,F(000)=1532. The distinguishing features of tris(3-methylpyridinium)(3-ethylpyridinium) β-octamolybdate monohydrate are its non-centrosymmetric polyanion and its extensive hydrogen bonding. The asymmetric unit contains three independent 3-methylpyridinium and one 3-ethylpyridinium cations, one water molecule and the β-octamolybdate anion. The planar cations are oriented to permit hydrogen bonds with either molybdate oxygen atoms or water oxygen atoms. Four different types of hydrogen bonds have been found: N−H...O (mono- and bifurcated); N−H...Ow (monofurcated); Ow−Hw...O (monofurcated); and C−H...O (monofurcated). The proposed hydrogen bonding interactions appear to stabilize the structure.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01022347
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