An Interesting Array of Cyclic Tetramer Water in the Molecular Structure of [V₆O₁₂(phen)₄(CH₃O)₄] · 4H₂O

A hydrothermal reaction of a mixture of Eu₂O₃, V₂O₅, 4,4′‐bpy, phen, HCl and ethylenediamine in methanol solution resulted in the unexpected complex, [V₆O₁₂(phen)₄(CH₃O)₄] · 4H₂O, which was then characterized by single‐crystal X‐ray diffraction. This complex crystallizes in the triclinic system with the space group P‐1 and cell parameters a=9.778(4) Å, b=11.620(5) Å, c=13.271(5) Å, α=73.433(8)°, β=77.068 (8)°, γ=87.509(8)°, and Z=2 with R₁=0.0726. Interestingly, a cyclic water tetramer is located in the packing diagrams of the title complex. The four water molecules linked by hydrogen bonds generate a two‐dimensional (2D) box structure, resulting in the formation of a square‐prism like water tetramer, which has not been experimentally observed and theoretically predicted so far.

Keywords:

• vanadium complex
• water tetramer
• crystal structure
• phenanthroline

We wish to express our sincere thanks to National Natural Science Foundation of China (No. 20571036), and SRF for ROCS, SEM for financial assistance.