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

Abstract

The space groups of {[Mo2(O2CCH3)4(`linker')] n } are corrected from P\bar 1 to C2/m for `linker' = pyrazine and 1,4-diazabicyclo[2.2.2]octane (dabco) and from P\bar 1 to C2/c for `linker' = 4,4′-bipyridine. Also, {[tris-(2-pyridylmethyl)amine]BrV(μ-O)VBr[tris-(2-pyridylmethyl)amine]}Br·H2O is corrected from P\bar1 to C2/c. These Laue class changes allow more reliable crystallochemical comparisons to be made among families of related structures. Space groups are correctedfor 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(2,2′-bi-1H-imidazole)bis[2-(2-1H-imidazolyl)-1H-imidazolium]bis(iodide)} corrects discrepancies of up to 0.38 Å between chemically similar hydrogen-bond distances. Wrongly identified atoms are corrected in θ-[bis(ethylenedithio)tetrathiafulvalene]2 (CsCd)(SCN)4 and (purported) diaquadihydroxotetrakis(m-nitrobenzenesulfonate)discandium(III). The reported difference between the crystal structure of (CH3NH3)4YbCl7 and those of the other members of this family of (CH3NH3)4 MX 7 (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.