A Novel Three‐Dimensional Copper(II) 1, 2‐Ethylenediphosphonate Framework with Channel‐like Voids. Issue 19 (5th September 2016) - Köferstein, Roberto
Abstract: Turquoise monoclinic single crystals of the novel three‐dimensional Cu2 [μ8 ‐O3 P(CH2 )2 PO3 ]· 3.2H2 O coordination polymer were prepared using the silica gel method. Space group C 2/ m (no. 12) with a = 1483.6(2), b = 668.44(8), c = 436.30(6) pm, β = 93.28(2)°. The Cu 2+ cation is coordinated by four oxygen atoms stemming from the 1, 2‐ethylenediphosphonate dianions in a square planar manner and two water molecules in the axial positions. The connection between the Cu 2+ cations and the [CPO3 ] units from the 1, 2‐ethylenediphosphonate dianions leads to layers parallel to (100), which are linked by the ethylene groups to a three‐dimensional framework with channel‐like voids. The channel‐like voids accommodate water molecules not bound to Cu 2+ and extend parallel to [001] with an opening of about 550 pm × 260 pm. Magnetic measurements reveal an antiferromagnetic behavior due to a superexchange coupling between Cu 2+ ions through an oxygen bridge. The UV/Vis spectrum reveals three d–d transition bands at 694, 774, and 918 nm. The compound can be fully dehydrated by thermal treatment and rehydrated by storage in ambient air. Abstract :