Toward Carbohydrate Derivatives with a Markedly Acidic Centre: Structures and Reactions of Selenium(IV) Diolates

Abstract

Keywords: Selenium / Carbohydrates / Density functional calculations / X-ray diffraction / Coordination induced shift Cyclic selenites, of the general formula (DiolH -2 )SeO, derived from the diols ethane-1,2-diol, propane-1,2-diol, cis-cyclopentane-1,2-diol, cis-cyclohexane-1,2-diol, trans-cyclohexane-1,2-diol, 1,1Ј-bicyclopentyl-1,1Ј-diol, 1,1Ј-bicyclohexyl-1,1Ј-diol, propane-1,3-diol, 2,2-dimethylpropane-1,3-diol, 1,1-bis(hydroxymethyl)cyclopropane, 1,1-bis(hydroxymethyl)cyclopentane, 1,4-anhydroerythritol and the methyl glycosides of β-D-ribofuranose, β-D-ribopyranose, α-D-mannopyranose, β-D-xylopyranose have been prepared and characterised by multinuclear NMR spectroscopy and single-

Zero-, one-, two- and three-dimensional supramolecular architectures sustained by Se…O chalcogen bonding: A crystallographic survey

“…The interactions selenium(VI) species form with oxygen reflect more conventional Lewis acid-Lewis base interactions. There are 18 selenium(IV) species, 33 – 50 [100] , [102] , [103] , [104] , [105] , [106] , [107] , [108] , [109] , [110] , [111] , [112] , [113] , [114] , [115] , and five selenium(VI) species, 51 – 55 [116] , [117] , [118] , [119] , forming Se … O contacts leading to zero-dimensional aggregates, with the chemical diagrams for the interacting species in these shown in Fig. 4 .…”

“…Each of 47 and 48 [113] assemble into tetrameric aggregates in the solid-state. In the crystal of 47 , there are two independent molecules in the asymmetric unit.…”

“…Two engage as shown in Fig. 5 i, while the other two engage to form a supramolecular chain as discussed below, see 175 [113] . The last two selenium(IV) aggregates to be described are hexameric.…”

“…The chemical diagrams for these species, i.e. 160 – 180 [93] , [104] , [105] , [113] , [188] , [206] , [207] , [208] , [209] , [210] , [211] , [212] , [213] , [214] , [215] , [216] , [217] , are shown in Fig. 15 .…”

“…16 e, the centrosymmetric aggregates are connected to translationally related dimers via a pair of Se … O(oxide) contacts so each selenium atom participates in three Se … O interactions. A more complicated mode of association between molecules occurs in 168 [113] , Fig. 16 f, for which two independent molecules comprise the asymmetric unit.…”