Solid State and Solution Mediated Multistep Sequential Transformations in Metal–Organic Coordination Networks

Sequential transformation in a family of metal–organic framework compounds has been investigated employing both a solid-state as well as a solution mediated route. The compounds, cobalt oxy-bis­(benzoate) and manganese oxy-bis­(benzoate) having a two-dimensional structure, were reacted with bipyridine forming cobalt oxy-bis­(benzoate)-4,4′-bipyridine and manganese oxy-bis­(benzoate)-4,4′-bipyridine, respectively. The bipyridine containing compounds appear to form sequentially through stable intermediates. For the cobalt system, the transformation from a two-dimensional compound, [Co­(H₂O)₂(OBA)] (OBA = 4,4′-oxy-bis­(benzoate)), <b>I</b>, to two different three-dimensional compounds, [Co­(bpy)­(OBA)]·bpy, <b>II</b>, (bpy = 4,4′-bipyridine) and [Co­(bpy)_0.5(OBA)], <b>III</b>, and reversibility between <b>II</b> and <b>III</b> have been investigated. In the manganese system, transformation from a two-dimensional compound, [Mn­(H₂O)₂(OBA)], <b>Ia</b>, to two different three-dimensional compounds, [Mn (bpy)­(OBA)]·bpy, <b>IIa</b> and <b>IIa</b> to [Mn­(bpy)_0.5(OBA)], <b>IIIa</b>, has been investigated. It has also been possible to identify intermediate products during these transformation reactions. The possible pathways for the formation of the compounds were postulated

Solid State and Solution Mediated Multistep Sequential Transformations in Metal–Organic Coordination Networks

Sequential transformation in a family of metal–organic framework compounds has been investigated employing both a solid-state as well as a solution mediated route. The compounds, cobalt oxy-bis­(benzoate) and manganese oxy-bis­(benzoate) having a two-dimensional structure, were reacted with bipyridine forming cobalt oxy-bis­(benzoate)-4,4′-bipyridine and manganese oxy-bis­(benzoate)-4,4′-bipyridine, respectively. The bipyridine containing compounds appear to form sequentially through stable intermediates. For the cobalt system, the transformation from a two-dimensional compound, [Co­(H₂O)₂(OBA)] (OBA = 4,4′-oxy-bis­(benzoate)), <b>I</b>, to two different three-dimensional compounds, [Co­(bpy)­(OBA)]·bpy, <b>II</b>, (bpy = 4,4′-bipyridine) and [Co­(bpy)_0.5(OBA)], <b>III</b>, and reversibility between <b>II</b> and <b>III</b> have been investigated. In the manganese system, transformation from a two-dimensional compound, [Mn­(H₂O)₂(OBA)], <b>Ia</b>, to two different three-dimensional compounds, [Mn (bpy)­(OBA)]·bpy, <b>IIa</b> and <b>IIa</b> to [Mn­(bpy)_0.5(OBA)], <b>IIIa</b>, has been investigated. It has also been possible to identify intermediate products during these transformation reactions. The possible pathways for the formation of the compounds were postulated

Synthesis, Structure, and Magnetic Properties of a New Eight-Connected Metal–Organic Framework (MOF) based on Co₄ Clusters

A hydrothermal reaction of cobalt nitrate, 4,4′-oxybis­(benzoic acid) (OBA), 1,2,4-triazole, and NaOH gave rise to a deep purple colored compound [Co₄(triazolate)₂(OBA)₃], <b>I</b>, possessing Co₄ clusters. The Co₄ clusters are connected together through the tirazolate moieties forming a two-dimensional layer that closely resembles the TiS₂ layer. The layers are pillared by the OBA units forming the three-dimensional structure. To the best of our knowledge, this is the first observation of a pillared TiS₂ layer in a metal–organic framework compound. Magnetic studies in the temperature range 1.8–300 K indicate strong antiferromagetic interactions for Co₄ clusters. The structure as well as the magnetic behavior of the present compound has been compared with the previously reported related compound [Co₂(μ₃-OH)­(μ₂-H₂O)­(pyrazine)­(OBA)­(OBAH)] prepared using pyrazine as the linker between the Co₄ clusters

Synthesis, Structure, and Magnetic Properties of a New Eight-Connected Metal–Organic Framework (MOF) based on Co₄ Clusters

A hydrothermal reaction of cobalt nitrate, 4,4′-oxybis­(benzoic acid) (OBA), 1,2,4-triazole, and NaOH gave rise to a deep purple colored compound [Co₄(triazolate)₂(OBA)₃], <b>I</b>, possessing Co₄ clusters. The Co₄ clusters are connected together through the tirazolate moieties forming a two-dimensional layer that closely resembles the TiS₂ layer. The layers are pillared by the OBA units forming the three-dimensional structure. To the best of our knowledge, this is the first observation of a pillared TiS₂ layer in a metal–organic framework compound. Magnetic studies in the temperature range 1.8–300 K indicate strong antiferromagetic interactions for Co₄ clusters. The structure as well as the magnetic behavior of the present compound has been compared with the previously reported related compound [Co₂(μ₃-OH)­(μ₂-H₂O)­(pyrazine)­(OBA)­(OBAH)] prepared using pyrazine as the linker between the Co₄ clusters