Journal
CHEMISTRY-A EUROPEAN JOURNAL
Volume 22, Issue 39, Pages 13900-13907Publisher
WILEY-V C H VERLAG GMBH
DOI: 10.1002/chem.201602341
Keywords
crystal engineering; crystal growth; isomers; magnetic properties; supramolecular interactions
Categories
Funding
- National Science Foundation for Distinguished Young Scholars of China [21525101]
- NSF of China and Guangxi Province [91122032, 2014GXNSFFA118003]
- BAGUI scholar program [2014A001]
- Project of Talents Highland of Guangxi Province
- Opening Project of Wuhan National High Magnetic Field Center [2015KF05]
- Huazhong University of Science and Technology
- CNRS-France
Ask authors/readers for more resources
Two polymorphs of supramolecular isomers, a discrete dimer and a zig-zag chain, having the same chemical composition, [Mn(Hbit)Cl-2] (Hbit= 1-methyl-2-(1H-1,2,3-triazol- 4-yl)-1H-benzo[d] imidazole), were obtained solvothermally in a one-pot synthesis. The isomers differ in a number of ways: orange blocks versus pale-yellow needles, triclinic P1 _ versus orthorhombic Pbcn, double mu(2)-Cl versus alternate single and triple mu(2)-Cl, coordination number 5 versus 6, and antiparallel versus parallel near-neighbor orientation of Hbit. The packing in each case is driven by the supramolecular interactions, H-bonds (N-H center dot center dot center dot Cl, C-H center dot center dot center dot Cl) and p center dot center dot center dot p overlaps, calculated to be in the range 20-36 kcal mol(-1). Calculations gave a difference of only 2 kcalmol(-1) in favor of the dimer, which confirms with the observation of principally the dimer at short reaction time. ESI-MS spectra of the dissolved crystals reveal the same fragments with similar distributions. The presence of two fragments at m/z 286.96 [MnIV(Hbit) Cl-2H]+ and 323.94 [MnIII(Hbit) Cl2](+) indicates that [Mn(Hbit) Cl-2] is the building unit in both cases; thus, the different orientations of the ligands lead to the two polymorphs stabilized by the respective supramolecular interactions. Importantly, the chain form represents the first example with alternate single and triple m2-Cl bridges. The magnetic interactions are weakly antiferromagnetic in both cases, with J in the range 0.07-0.34 cm(-1); however, high-field EPR analysis reveals moderate magneto-anisotropy with D= 0.26(1) cm(-1), E= 0.06(1) cm(-1) and D= 0.17(1) cm(-1), E= 0.03(1) cm(-1), respectively.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available