Some errors from the crystallographic literature, some amplifications and a questionable result

摘要

The space groups of {[Mo-2(O2CCH3)(4)('linker')](n)}are corrected from P (1) over bar to C2/m for 'linker' = pyrazine and 1,4-diazabicyclo[2.2.2]octane (dabco) and from P (1) over bar 1 to C2/c for 'linker' = 4,4'-bipyridine. Also, {[tris-(2-pyridylmethyl)amine]-BrV(mu-O)VBr[tris-(2-pyridylmethyl)amine]}B r.H2O is corrected from P (1) over bar to C2/c. These Laue class changes allow more reliable crystallochemical comparisons to be made among families of related structures. Space groups are corrected for 4-methyl-2,6-bis(4-methylbenzylidene)cyclohexanone, 2,6-bis(4-dimethylaminobenzylidene)cyclohexanone, K[Cr(tetramethylenediamine-N,N,N', N'-tetraacetate)].H2O and {bis(11,11-dimethyl-3,4:8,9-dibenzobicyclo[4.4.1]undeca-3,8-diene)- (tetracyanoethylene)}. The conflicting reports for Cu(H2O)(phenanthroline)(2) (X)(2), where X = ClO4, NO3 and BF4, are resolved. Three related examples of open framework host-guest structures with space groups 'Cc or C2/c' are discussed. Adding centers to 2,2'-bi-1H-imidazolium dipicrate and {tris(2,20 -bi-1H-imidazole)bis[2-(2-1H-imidazolyl)-1H-imidazolium]bis(iodide)} corrects discrepancies of up to 0.38 Angstrom between chemically similar hydrogen-bond distances. Wrongly identified atoms are corrected in theta-[bis(ethylenedithio)tetrathiafulvalene]2 (CsCd)(SCN)(4) and (purported) diaquadihydroxotetrakis (m-nitrobenzenesulfonate) discandium(III). The reported difference between the crystal structure of (CH3NH3)(4)YbCl7 and those of the other members of this family of (CH3NH3)(4)MX7 (M = In, Fe, V; X = Cl, Br) structures is pointed out in the context of possibly different N-H...Cl hydrogen bonding in the Yb structure. [References: 41]