Crystal Structure, Synthesis, and Properties of tri‐Calcium di‐Citrate tetra‐Hydrate [Ca3(C6H5O7)2(H2O)2]·2H2O

Abstract From hydrothermal synthesis needle‐shaped crystals of [Ca 3 (C 6 H 5 O 7 ) 2 (H 2 O) 2 ] · 2H 2 O were obtained. The crystal structure was determined by single‐crystal X‐ray experiments and confirmed by powder data ( P $\bar{1}$ (no. 2) a = 5.9466(4), b = 10.2247(8), c = 16.6496(13) Å, α = 72.213(7)°, β = 79.718(7)°, γ = 89.791(6)°, V = 947.06(13) Å 3 , Z = 2, R 1 = 0.0426, wR 2 = 0.1037). The structure was obtained from pseudo merohedrically polysynthetic twinned crystals using a combined data collection approach and refinement processes. The observed three‐dimensional network is dominated by eightfold coordinated Ca 2+ cations linked by citrate anions and hydrogen bonds between two non‐coordinating crystal water molecules and two coordinating water molecules.