Two borophosphates, (NH)M(HO)(BPO)·yHO with M = Mn (I) and Co (II), synthesized hydrothermally crystallize in enantiomorphous space groups P622 and P622 with a = 9.6559(3) and 9.501(3) Å, c = 15.7939(6) and 15.582(4) Å, and V = 1275.3(1) and 1218.2(8) Å for I and II, respectively. Both compounds feature helical chains composed of vertex-sharing tetrahedral PO and BO groups that are connected through O atoms to transition-metal cations, Mn and Co, respectively. For the two crystallographically distinct transition-metal cation sites present in the structure, this results in octahedral coordination with different degrees of distortion from the ideal symmetry. The crystal-field parameters, calculated from the corresponding absorption spectra, indicate that Mn and Co ions are located in a weak octahedral-like crystal field and suggest that the Co-ligand interactions are more covalent than the Mn-ligand ones. Luminescence measurements at room temperature reveal an orange emission that red-shifts upon lowering of the temperature to 77 K for I, while II is not luminescent. The luminescence lifetimes of I are 33.4 μs at room temperature and 1.87 ms at 77 K. Both compounds are Curie-Weiss paramagnets with negative Weiss constants and effective magnetic moments expected for noninteracting Mn and Co cations but no clear long-range magnetic order above 2 K.

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