Synthesis and Characterization of Coordination Polymers and Studies for CO2 Capture

The work in this dissertation is presented in two sections. Section 1 investigates the use of large metal cations in the construction of coordination polymers. Section 2 focuses on the synthesis of functionalized linkers for the construction of metal-organic frameworks (MOFs) for CO2 uptake.

Chapters 2 and 3 describe work done on alkali metal aryloxide systems. Our group has previously shown alkali metal aryloxide aggregates are good candidates as secondary building units in the construction of coordination polymers. The majority of the previous work was done with lithium and sodium. The work described in Chapters 2 and 3 details the synthesis and structural characterization of potassium, rubidium and cesium phenoxide materials. A set of isostructural potassium, rubidium and cesium 4-ethylphenoxide species form 1-D inorganic rods, which are subsequently linked together to form 3-D hybrid organic-inorganic materials. Also, a series of three new cesium 2-iso-propylphenoxide materials has been characterized. Two of the three species are hybrid organic-inorganic materials constructed of 1-D inorganic rods. Formation of 1-D inorganic rods is an emerging trend for large alkali metal phenoxide systems.

The final portion of Section 1 discusses work performed with various large metal cations including potassium, barium, lanthanum, cerium, neodymium and gadolinium. Prepared materials include 1-D chains, 2-D sheets, and 3-D networks. A homologous series of 2-D sheets is described in Chapter 4. The materials, [{LnX(C10H8N2O2)4(CH3OH)}2+{B(Ph)4}2-'¢(CH3OH)] (Ln = La, X + Cl; Ln = Ce, X = Br; Ln = Gd, X = Cl), form 2-D square nets in which the lanthanide is bridged to four neighboring metal centers through 4,4'-dipyridyl-N,N'-dioxide linkers. Chapter 5 details the structural characterization of three interesting solids, a 1-D neodymium benzoate material, a 3-D potassium network and a 3-D barium material composed of a highly charged [Ba2(C10H8N2O2)6]4+ network with a polymeric [Ba2(NO3)8]4- anion in the channels.

Section 2 describes the synthesis, characterization and deprotonation studies on imidazolium based organic molecules and their use as linkers for the construction of MOFs for CO2 uptake. Five imidazolium based organic linking molecules have been synthesized. These linkers were used in the construction of 1-D, 2-D, and 3- D MOFs. Two of the 2-D materials, [La3(HL1Br)2(L1)(OH)3] 7.3 and [Nd(HL1Br)1.5(H2O)1.5] 7.4, are very similar and are constructed of 1-D lanthanide-carboxylate chains. A related 3-D material, [Nd2(HL1Br)3(bipy)0.5] 7.5, is constructed of 2-D sheets nearly identical to those in 7.4 which are connected through 4,4'-bipyridine linkers.