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Alkali‐Metal ortho ‐Hydroxyphenolates: Syntheses and Crystal Structures from Powder X‐Ray Diffraction
Author(s) -
Couhorn Uwe,
Dronskowski Richard
Publication year - 2003
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/zaac.200300249
Subject(s) - monoclinic crystal system , orthorhombic crystal system , crystallography , alkali metal , rietveld refinement , catechol , hydrogen bond , crystal structure , bond length , powder diffraction , x ray crystallography , chemistry , molecular geometry , materials science , diffraction , molecule , organic chemistry , physics , optics
Colorless and highly air‐ and moisture‐sensitive powders of M[ o ‐C 6 H 4 O(OH)] with M = K, Rb, or Cs have been synthesized from reaction mixtures of the appropriate alkali metal and catechol in thf. All compounds were structurally characterized by means of powder X‐ray diffraction using the Rietveld profile refinement technique including restraints for the C—C/C—O bond distances and the C—C—C angles. The atomic arrangements of M[ o ‐C 6 H 4 O(OH)] (K: monoclinic P 2 1 / c ; Rb/Cs: orthorhombic Pbcm ) are characterized by polymeric chains of ∞ 1 [M 1 [4] O 2 [2] η 6 ] units connected by hydrogen bonds, thereby making up layered structures similar to the one of catechol. The coordinatively unsaturated alkali metals are forming edge‐sharing MO 4 pyramids and exhibit asymmetrical η 6 ‐interactions with the phenylene rings. The symmetry of the unit cells increases with increasing size of the cation, and this results in a decrease of the monoclinic angle from 118.5° (catechol) to 93.7° (K compound), eventually leading to orthorhombic cells for the Rb and Cs compounds.