Discrete Oligomers and Polymers of Chloride Monohydrate Can Form in Encapsulated Environments: Structures and Infrared Spectra of [Cl-4(H2O)(4)](4-) and {[Cl(H2O)](-)}(infinity)

A discrete tetrachloride tetrahydrate cluster, [Cl-4(H2O)(4)](4-), was obtained with a partially-fluorinated triaminocyclopropenium cation, [C-3(N(CH2CF3)(2))(NEt2)(NPr2)](+). The cluster consists of a [Cl-2(H2O)(2)](2-) square with each Cl- coordinated by another H2O bridged to another Cl-. A 1D polymer of chloride monohydrate, {[Cl(H2O)](-)}(infinity), was obtained with [C-3(N(CH2CF3)(2))(2)(NBuMe)](+). The tetrameric and polymeric structures were found to be computationally-unstable in the gas phase which indicates that an encapsulated environment is essential for their isolation. DFT and DFTB calculations were carried out on gas-phase [Cl-4(H2O)(4)](4-) to assist the infrared assignments. Anharmonically-corrected B3LYP transition frequencies were in close agreement with experiment, but DFTB models were only appropriate for qualitative interpretation. Solid-state DFTB calculations allowed the vibrational modes to be assigned. The results found are consistent with "discrete" chloride hydrates.