Synthesis, Crystal Structure, and Characterization of a New Metal Borophosphate: Pb II 4 {Co 2 [B(OH) 2 P 2 O 8 ](PO 4 ) 2 }Cl

Abstract A new metal borophosphate Pb II 4 {Co 2 [B(OH) 2 P 2 O 8 ](PO 4 ) 2 }Cl ( 1 ), containing both Pb 2+ cations and Cl – anions, was hydrothermally synthesized and characterized by powder X‐ray diffraction, ICP, TG/DTA, and FTIR spectroscopic analyses. The crystal structure determination from single‐crystal X‐ray diffraction reveals that compound 1 crystallizes in the trigonal space group R $\bar{3}$ c (No. 167), a = 9.7513(7) Å, c = 91.060(13) Å, V = 7498.7(13) Å 3 and Z = 18. Its structure features a new cobalt borophosphate layer {Co 2 [B(OH) 2 P 2 O 8 ](PO 4 ) 2 } 7– built up from CoO 5 square pyramids, [B(OH) 2 P 2 O 8 ] 5– borophosphate trimers and PO 4 tetrahedra. Extra‐framework Pb 2+ and Cl – ions are located at the vacancy of layers to achieve the charge neutrality of the framework. Magnetic measurements indicate that antiferromagnetic interactions exist between Co 2+ ions with a negative Weiss constant of –20.3 K.