Hydrothermal chemistry of Th(IV) with aromatic dicarboxylates: New framework compounds and in situ ligand syntheses

Journal Article · Fri Feb 15 04:00:00 EST 2008 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2007.12.008· OSTI ID:21043901

Ziegelgruber, Kate L ^[1]; Knope, Karah E; Frisch, Mark ^[2]; Cahill, Christopher L ^[2]

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1. Department of Chemistry and Biochemistry, DePauw University, Greencastle, IN 46135 (United States)
2. Department of Chemistry, George Washington University, Washington, DC 20052 (United States)

A novel thorium (IV) coordination polymer, Th(C{sub 5}H{sub 2}N{sub 2}O{sub 4}){sub 2}(H{sub 2}O){sub 2} (1), has been prepared under the hydrothermal reaction of thorium nitrate tetrahydrate and 3,5-pyrazoledicarboxylic acid (H{sub 3}pdc). Compound 1 (orthorhombic, P2{sub 1}2{sub 1}2{sub 1}, a=6.9362(5) A, b=10.7806(8) A, c=17.9915(14) A, Z=2, R{sub 1}=0.0210, wR{sub 2}=0.0470) consists of thorium metal centers connected via H{sub 3}pdc linkages to form an overall three-dimensional structure containing {pi}-{pi} interactions between the pyrazole rings. 2,3-Pyrazinedicarboxylic acid (H{sub 2}pzdc) was explored as well to (1) study the effect of the location of the carboxylic groups around the aromatic ring and (2) produce heterometallic compounds. Thorium (IV) and copper (II) were combined with H{sub 2}pzdc, resulting in an interesting decomposition reaction characterized though the isolation of Th(C{sub 2}O{sub 4}){sub 2}(H{sub 2}O){sub 2}.2H{sub 2}O (2) (monoclinic, C2/c, a=13.8507(12) A, b=7.8719(7) A, c=10.7961(16) A, {beta}=118.0310(10){sup o}, Z=2, R{sub 1}=0.0160, wR{sub 2}=0.0349), Cu(C{sub 6}H{sub 2}N{sub 2}O{sub 4}) (3) (monoclinic, C2/c, a=11.499(3) A, b=7.502(2) A, c=7.402(2) A, {beta}=93.892(5){sup o}, Z=4, R{sub 1}=0.0472, wR{sub 2}=0.0745) and Cu(C{sub 5}H{sub 3}N{sub 2}O{sub 2})(NO{sub 3})(H{sub 2}O) (4). The capture of these species provides mechanistic evidence for the formation of the oxalate anions observed in 2 via the decarboxylation of H{sub 2}pzdc to yield the linker in 4: 2-pyrazinecarboxylate anions. - Graphical abstract: 3,5-Pyrazoledicarboxylic and 2,3-pyridinedicarboxylic acid were utilized in synthesizing two novel thorium (IV) coordination polymers. Attempts to synthesize a Th-Cu bimetallic compound with 2,3-pyridinedicarboxylic acid resulted in a triphasic mixture (2, 3 and 4, respectively). The oxalate anion observed in Th(C{sub 2}O{sub 4}){sub 2}(H{sub 2}O){sub 2}.2H{sub 2}O (2) is theorized to result from decarboxylation of 2,3-pyridinedicarboxylic acid as supported by the organic linker, 2-pyrazinecarboxylate, observed in Cu(C{sub 5}H{sub 3}N{sub 2}O{sub 2})(NO{sub 3})(H{sub 2}O) (4)

• OSTI ID: 21043901
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 181; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ANIONS
DECARBOXYLATION
HYDROTHERMAL SYNTHESIS
LIGANDS
MONOCLINIC LATTICES
ORTHORHOMBIC LATTICES
OXALATES
POLYMERS
PYRAZOLES
THORIUM COMPLEXES
THORIUM NITRATES
WATER