Functional materials through coordination chemistry: New rhenium-containing metal-cyanide complexes, clusters, and solids

Within this dissertation, synthetic routes to magnetic and porous materials through the coordination chemistry of metal-cyanide complexes are described. An overview of the history and properties of the oldest known metal-cyanide framework, Prussian blue, is given in Chapter 1. Potential applications of cyanide-based compounds are then discussed.; Chapter 2 details the synthesis and properties of two new homoleptic rheniumcyanide complexes: [Re(CN)7]3- and [Re(CN)8]3-. The former species is the first paramagnetic ReIV cyanide complex to be reported. Incorporation of this anisotropic building block into solids should lead to strong magnetic coupling and high coercive fields. The solid [cis-Mn(H 2O)2][fac-Mn(H2O)3][Re(CN) 7] has been isolated in which the rhenium center has been reduced by one electron. Attempts to prevent reduction of the ReIV center with strong oxidants led to isolation of the first eight coordinate rhenium-cyanide complex, [Re(CN)8]3-.; The photochemistry of [Re(CN)8]3- is discussed in Chapter 4. The photo-reduction or oxidation of the diamagnetic complex when incorporated into clusters or solids can lead to photo-induced magnetism. The reaction of [Re(CN)8]3- with Mn2+ or Ni2+ yields large M 9[Re(CN)8]6 clusters. Upon irradiation with ultraviolet light, magnetic exchange coupling in a portion of the clusters occurs. This is one of the first examples of a photomagnetic cluster.; The synthesis and coordination chemistry of the new magnetic building block trans-[Re(CN)2Cl4]2- are presented in Chapter 4. The axial zero-field splitting parameter of this compound is D = -12.5 cm-1, the highest measured for a cyanide complex to my knowledge. Coordination of the metal with chloride as well as cyanide stabilizes the highly charged core against reduction to lower valent, diamagnetic oxidation states. Indeed, this compound has been incorporated into clusters containing Ni2+, which possess the highest magnetic anisotropy of any transition-metal cyanide cluster.; Chapters 5 and 6 contain reports of the expansion of transition-metal cyanide frameworks such as Na2Zn3[Fe(CN)6] 2·9H2O, Fe4[Fe(CN)6]3·14H 2O, and Ni3[Fe(CN)6]2·14H 2O by substitution of [Fe(CN)6]3-/4- with [Re6Se8(CN)6]3-/4- . The pore sizes of the expanded solids are on the order of those found in zeolites, such that full coordination complexes can be exchanged into the Na2Zn3[Re6Se8(CN) 6]2·24H2O. The syntheses and single crystal structures of this framework and [Zn(H2O)6]Zn3 [Re6Se8(CN)6]2·24H 2O are reported in Chapter 5. The generality of this technique is presented in Chapter 6 along with the most porous metal-cyanide solid on record: Ni 3[Re6Se8(CN)6]2·33H 2O.; In addition, a number of new coordination complexes, clusters, and cluster-expanded solids are reported in four appendices.