Crystal Structures and Intermolecular Interactions in $\alpha$ - and $\beta$ -phosgene.

ABSTRACT: The crystal structures of α$\alpha$ - and β$\beta$ -phosgene have been elucidated on the basis of variable temperature neutron powder diffraction. Although the stable α$\alpha$ -phase closely mirrors the published structure ( I41/a$I4_1/a$ , No. 88), the new metastable β$\beta$ -phase crystallises in Cmc21$Cmc2_1$ (No. 36, at 135 K: a = 10.244042(22) Å, b = 6.280321(21) Å, c = 5.46069(4) Å). Both modifications show dipole-dipole interactions, but only α$\alpha$ -phosgene shows pronounced σ$\sigma$ -hole interactions. Quantum chemical calculations in both solid state and of model dimers in gas-phase reveal a complex interplay of intermolecular interactions. The first inelastic neutron scattering spectra of α$\alpha$ -phosgene shows an unusual separation of the translational and librational

SUBMITTER: Ringelband S 

PROVIDER: S-EPMC12790384 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature