Rational design of single-molecule magnets: a supramolecular approach

Glaser T (2011)
Chemical Communications 47(1): 116-130.

Journal Article | Published | English

No fulltext has been uploaded

Abstract
Since the discovery that Mn12OAc acts as a single-molecule magnet (SMM), an increasing number of transition metal complexes have been demonstrated to behave as SMMs. The signature of a SMM is a slow relaxation of the magnetization at low temperatures accompanied by a magnetic hysteresis. The origin of SMM behaviour is the existence of an appreciable thermal barrier U for spin-reversal called magnetic anisotropy barrier which is related to the combination of a large total spin ground state (S-t) and an easy-axis magnetic anisotropy. The extensive research on Mn12OAc and other SMMs has established more prerequisites for a rational development of new SMMs besides the high-spin ground state and the magnetic anisotropy: the symmetry should be at least C-3 to minimize the quantum tunneling of the magnetization through the anisotropy barrier but lower than cubic to avoid the cancellation of the local anisotropies upon projection onto the spin ground state. Based on these prerequisites, we have designed the ligand triplesalen which combines the phloroglucinol bridging unit for high spin ground states by the spin-polarization mechanism with a salen-like ligand environment for single-site magnetic anisotropies by a strong tetragonal ligand field. The C-3 symmetric, trinuclear complexes of the triplesalen ligand (talen(t-Bu2))(6-) exhibit a strong ligand folding resulting in an overall bowl-shaped-molecular structure. This ligand folding preorganizes the axial coordination sites of the metal salen subunits for the complementary binding of three facial nitrogen atoms of a hexacyanometallate unit. This leads to a high driving force for the formation of heptanuclear complexes [(M6Mc)-M-t](n+) by the assembly of three molecular building blocks. Attractive van der Waals interactions of the tert-butyl phenyl units of two triplesalen trinuclear building blocks increase the driving force. In this respect, we have been able to synthesize the isostructural [(Mn6CrIII)-Cr-III](3+), [(Mn6FeIII)-Fe-III](3+), and [(Mn6CoIII)-Co-III](3+) with [(Mn6CrIII)-Cr-III](3+) being a SMM. A detailed analysis and comparison of the magnetic properties of the three heptanuclear complexes and the tetranuclear half-unit [(Mn3CrIII)-Cr-III](3+) provides significant insight for further optimization of the SMM properties. The modular assembly of the heptanuclear complexes from three molecular building blocks allows the fine-tuning of the molecular and steric properties of each building block without losing the driving force for the formation of the heptanuclear complexes. This possibility of rational improvements of our isostructural series is the main advantage of our supramolecular approach.
Publishing Year
ISSN
eISSN
PUB-ID

Cite this

Glaser T. Rational design of single-molecule magnets: a supramolecular approach. Chemical Communications. 2011;47(1):116-130.
Glaser, T. (2011). Rational design of single-molecule magnets: a supramolecular approach. Chemical Communications, 47(1), 116-130.
Glaser, T. (2011). Rational design of single-molecule magnets: a supramolecular approach. Chemical Communications 47, 116-130.
Glaser, T., 2011. Rational design of single-molecule magnets: a supramolecular approach. Chemical Communications, 47(1), p 116-130.
T. Glaser, “Rational design of single-molecule magnets: a supramolecular approach”, Chemical Communications, vol. 47, 2011, pp. 116-130.
Glaser, T.: Rational design of single-molecule magnets: a supramolecular approach. Chemical Communications. 47, 116-130 (2011).
Glaser, Thorsten. “Rational design of single-molecule magnets: a supramolecular approach”. Chemical Communications 47.1 (2011): 116-130.
This data publication is cited in the following publications:
This publication cites the following data publications:

31 Citations in Europe PMC

Data provided by Europe PubMed Central.

Nanorings and rods interconnected by self-assembly mimicking an artificial network of neurons.
Escarcega-Bobadilla MV, Zelada-Guillen GA, Pyrlin SV, Wegrzyn M, Ramos MM, Gimenez E, Stewart A, Maier G, Kleij AW., Nat Commun 4(), 2013
PMID: 24177669
Single-molecule magnets: Iron lines up.
Bill E., Nat Chem 5(7), 2013
PMID: 23787742
A new family of trinuclear nickel(II) complexes as single-molecule magnets.
Biswas R, Ida Y, Baker ML, Biswas S, Kar P, Nojiri H, Ishida T, Ghosh A., Chemistry 19(12), 2013
PMID: 23362190
Versatile switching in substrate topicity: supramolecular chirality induction in di- and trinuclear host complexes.
Escarcega-Bobadilla MV, Salassa G, Martinez Belmonte M, Escudero-Adan EC, Kleij AW., Chemistry 18(22), 2012
PMID: 22522915

160 References

Data provided by Europe PubMed Central.


Glaser, Angew. Chem., Int. Ed. 45(), 2006

Krickemeyer, Z. Naturforsch., B: Chem. Sci. 65(), 2010

Hoeke, 0

Shen, Transition Met. Chem. 27(), 2002

Choi, J. Phys. Chem. Solids 65(), 2004

Richthofen, Inorg. Chem. 48(), 2009

Glaser, C. R. Chim. 10(), 2007

Theil, 0

Export

0 Marked Publications

Open Data PUB

Web of Science

View record in Web of Science®

Sources

PMID: 20862425
PubMed | Europe PMC

Search this title in

Google Scholar