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Thermally Triggered Solid-State Single-Crystal-to-Single-Crystal Structural Transformation Accompanies Property Changes.
- Source :
- Chemistry - A European Journal; Mar2015, Vol. 21 Issue 12, p4703-4711, 9p
- Publication Year :
- 2015
-
Abstract
- The 1D complex [(CuL<subscript>0.5</subscript>H<subscript>2</subscript>O) ⋅H<subscript>2</subscript>O]<subscript> n</subscript> ( 1) (H<subscript>4</subscript>L=2,2′-bipyridine-3,3′,6,6′-tetracarboxylic acid) undergoes an irreversible thermally triggered single-crystal-to-single-crystal (SCSC) transformation to produce the 3D anhydrous complex [CuL<subscript>0.5</subscript>]<subscript> n</subscript> ( 2). This SCSC structural transformation was confirmed by single-crystal X-ray diffraction analysis, thermogravimetric (TG) analysis, powder X-ray diffraction (PXRD) patterns, variable-temperature powder X-ray diffraction (VT-PXRD) patterns, and IR spectroscopy. Structural analyses reveal that in complex 2, though the initial 1D chain is still retained as in complex 1, accompanied with the Cu-bound H<subscript>2</subscript>O removed and new O(carboxyl)Cu bond forming, the coordination geometries around the Cu<superscript>II</superscript> ions vary from a distorted trigonal bipyramid to a distorted square pyramid. With the drastic structural transition, significant property changes are observed. Magnetic analyses show prominent changes from antiferromagnetism to weak ferromagnetism due to the new formed Cu1-O-C-O-Cu4 bridge. The catalytic results demonstrate that, even though both solid-state materials present high catalytic activity for the synthesis of 2-imidazolines derivatives and can be reused, the activation temperature of complex 1 is higher than that of complex 2. In addition, a possible pathway for the SCSC structural transformations is proposed. [ABSTRACT FROM AUTHOR]
- Subjects :
- CRYSTAL structure
X-ray diffraction
THERMOGRAVIMETRY
BIPYRIDINE
ANTIFERROMAGNETISM
Subjects
Details
- Language :
- English
- ISSN :
- 09476539
- Volume :
- 21
- Issue :
- 12
- Database :
- Complementary Index
- Journal :
- Chemistry - A European Journal
- Publication Type :
- Academic Journal
- Accession number :
- 101385671
- Full Text :
- https://doi.org/10.1002/chem.201405984