October 1998 issue
cif-access (metal-organic compounds)
The title complex consists of infinite positively charged [Sc2(Gly)6]n (Gly = glycine) chains and ClO4− anions. The Sc3+ ions in the [Sc2(Gly)6]n chains are linked by glycine molecules and are octahedrally coordinated by glycine O atoms.
This compound belongs to a family of dimeric clusters formed through bonding of electron-rich iron carbonyls to electron-deficient thallium. Pressurization under CO of the thallium-iron carbonyl [Et4N]2[Fe4Tl2(CO)16] yielded crystals of [Et4N]2[Fe6Tl2(CO)24], which crystallizes in the orthorhombic centrosymmetric space group Cmca.
cif-access (organic compounds)
The crystal structure of 2-pyridinecarboxylic acid was redetermined to confirm the space group C2/c. However, a solid-state high resolution 15N CP-MAS NMR study indicated that neutral molecules and zwitterions are arranged alternately within local non-centrosymmetric domains.
On short-term heating, highly strained ap-9-(o-tert-butylphenyl)-9-(methylthio)fluorene underwent facile cleavage of the C-S bond. Migration of the methylthio group produced sp-9-(o-tert-butylphenyl)-3-(methylthio)fluorene as the major product. Its structure is much less distorted than that of the ap starting material.
The title compound crystallizes with two independent molecules per asymmetric unit. The molecules assume slightly different conformations. The crystallographically unique molecules stack in columns along the b axis. Close C-H⋯O contacts are observed between molecules related by a twofold screw axis. The absolute configuration was established by internal comparison with the (R)-(−)-O-methyl mandelic acid moiety.
Disodium zinc diphosphate may be doped with europium(III) to produce a red-emitting material, Na1.94Eu0.02ZnP2O7. Determination of the single-crystal X-ray structures of the doped and undoped forms shows them to be isostructural, with EuIII occupying a site of mm symmetry.
The structure of [Co(NO2)(NH3)5]Cl2 has been refined anisotropically from data collected at 0.24, 0.52, 1.25, 1.91 and 3.38 GPa in a diamond anvil cell. For comparison, the structure of the same crystal in the same diamond anvil cell was also refined at ambient pressure.