Open-framework transition metal fluorophosphates with one-dimensional antiferromagnetic chains

Open-Framework Iron Fluoride Phosphates Based on Chain, Trinuclear, and Tetranuclear Chain FeIII Building Units: Crystal Structures and Magnetic Properties

“…Four normal P-O/F bond distances range from 1.527(4) to 1.539(4) Å. However, the P2 atoms are coordinated tetrahedrally by three oxygen atoms and one terminal F atom with P–O bond distances of 1.514(4)–1.523(4) Å and one elongated P–F bond length of 1.559(4) Å, consistent with previously reported values for this structural unit. ,,, …”

“…A microwave frequency of ν 4) Å, consistent with previously reported values for this structural unit. 11,13,22,23 The structure of K 2 Fe(PO 2.5 F 1.5 ) 2 F 2 (II) consists of polyhedral KF 3 O 2 (O/F) 2 , octahedral trans-FeO 4 F 2 , and tetrahedral PO 2.5 F 1.5 building units (Figure 2a). The structure can be described as {Fe(PO 2.5 F 1.5 ) 2 F 2 } 2− chains oriented along the a direction in a rectangular plane grouped in a p2gg manner, formed by each trans-FeO 4 F 2 octahedral that is connected by two PO 2.5 F 1.5 tetrahedra via oxygen atoms (see Figure 2b), isolated by the KF Compound III can be regarded as a {Fe 3 (PO 4 )(PO 3 F) 2 F 4 } 3− macroanionic network, whose charge neutrality is balanced with K + ions (Figure 3a).…”