362nd WEH SEMINAR Advances and Prospects in Molecular MagnetismBad Honnef, 11 - 16 November 2005

Andrea CORNIA INSTM & Department of Chemistry, University of Modena & Reggio Emilia (Italy)

Organizing Single-Molecule Magnetson Surfaces

-3 -2 -1 0 1 2 3

-20

-10

0

10

20

Ma

gn

eti

za

tio

n (

µµ µµB)

Magnetic field (T)

2.1K

362nd WEH SEMINAR Advances and Prospects in Molecular MagnetismBad Honnef, 11 - 16 November 2005

C. Zanardi, L. ZobbiINSTM & Dept. of Chemistry, Univ. of Modena & Reggio Emilia, Italy

A. Caneschi, D. Gatteschi,M. Mannini, R. SessoliINSTM & Dept. of Chemistry, Univ. of Florence, Italy

B. Jan Ravoo, N.D. Reinhoudt, E.A. SpeetsLaboratory of Supramolecular Chemistryand Technology, MESA+ Institute forNanotechnology, University of Twente, The Netherlands

D. BarrecaISTM-CNR & INSTM, Departmentof Chemistry, University of Padova, Italy

E. TondelloINSTM & Department of Chemistry, University of Padova,

Italy

Outline1. The chemistry of Mn12 Single-Molecule Magnets

2. 2D domains of Single-Molecule Magnets

2.1 Motivation2.2 By surface pre-functionalization2.3 By direct deposition2.4 By Micro-Contact Printing

3. From densely-packed to isolated clusters

4. Conclusions & Perspectives

362nd WEH SEMINAR Advances and Prospects in Molecular MagnetismBad Honnef, 11 - 16 November 2005

Manganese(IV) (s = 3/2)

Manganese(III) (s = 2)

Oxygen

Carbon

Hydrogen

[Mn12O12(OAc)16(H2O)4]·2AcOH·4H2O

T. Lis, Acta Crystallogr. B. 1980, 36, 2042

S = 10 (Giant Spin)

Mn(OAc)2•4H2O + KMnO4

[Mn12O12(OAc)16(H2O)4]·2AcOH·4H2O (80%)

60% v/v AcOH/H2O

Ligand exchange

[Mn12O12(OAc)16(H2O)4] + xRCO2H [Mn12O12(OAc)16-x(O2CR)x(H2O)4] + xAcOH

toluene/AcOH azeotrope 72/28%, bp 100.6 oC (vs. 110.7 / 118.1oC)

[Mn12] + PPh4I PPh4[Mn12] +1/2I2

Redox

[Mn12O12]+ → [Mn12O12] → [Mn12O12]

- → [Mn12O12]2-→ [Mn12O12]

3-

Reactivity of [Mn12O12(OAc)16(H2O)4]

M. Soler, et al. Inorg.Chem. 2001,40,4902; H. J. Eppley, et al. J.Am.Chem.Soc. 1995,117,301

M. Pacchioni, et al. Chem. Commun. 2004, 2604.

[Mn12O12(OAc)16(H2O)4] + 16PhCO2H [Mn12O12(O2CPh)16(H2O)4] + 16AcOHtoluene

[Mn12O12(O2CPh)8(L)4(H2O)4] + 8PhCO2H[Mn12O12(O2CPh)16(H2O)4] + 4H2LCH2Cl2/hex

H2L[Mn12O12(O2CPh)8(L)4(H2O)4]

Reactivity of [Mn12O12(OAc)16(H2O)4]

2D Domains of Single-Molecule Magnets

Motivation

New Physics and Applications

� magnetic behaviour of “isolated” single-molecule magnets

� role of the environment

� writing and reading magnetic information on a single molecule

� ultra-high density information storage (10 Tbit/cm2)

•Langmuir-Blodgett films withbehenic acid (C21) M. Clemente-Leon et al., Angew. Chem. IE 1998, 37, 2842

•Photolithographically fabricated patterns on Si/SiO2K. Kim et al., Appl. Phys. Lett. 2004, 85, 3872

•Stamp–assisted deposition on Si/SiO2M. Cavallini et al., Nano Lett. 2003, 3, 1527

•Dispersions in polymersD. Ruiz–Molina et al., Adv. Mater. 2003, 15, 42 M. Cavallini et al., Angew. Chem. Int. Ed. 2005, 44, 888

solvent vapors

2D Domains of Single-Molecule Magnets

2D Domains of Single-Molecule Magnets

� Stable (sub)monolayers

� Covalently bound

� Oriented

� On conducting substrates

STMtip

Au

Pre-functionalized surfaces + Native clusters

Native surfaces + Pre-functionalized clusters

Pre-functionalized surfaces + Pre-functionalized clusters

Grafting on pre-functionalized Si(100) surfacesG. G. Condorelli et al.,Angew. Chem. Int. Ed. 2004, 43, 4081 [Mn12O12(O2CCH3)16(H2O)4]

B. Fleury et al.,Chem. Commun. 2005, 2020 [Mn12O12(O2CCHCl2)8(O2CCH2Bu

t)8(H2O)3]

AFM400 x 400 µm

AFM70 x 70 µm

2D Domains of Single-Molecule Magnets

J. S. Steckel et al., Nano Lett. 2004, 4, 399[Mn12O12(O2CCH3)16(H2O)4]

A. Nait Abdi et al., Adv. Mater. 2005, 17, 1612[Mn12O12(O2C

tBu)16(H2O)4]

Grafting on pre-functionalized Au(111) surfaces

Quartz Crystal Microbalance

2D Domains of Single-Molecule Magnets

16-(acetylthio)hexadecanoic acid

Mn12-bindinggroup

Au-bindinggroup

spacer

[Mn12O12(OAc)16(H2O)4] + 16RCO2H [Mn12O12(O2CR)16(H2O)4] +16AcOH

Direct Deposition on Au(111)

5.0 ×××× 5.6 nm

[Mn12O12(L)16] + H+

MALDI-TOF

[Mn12O12(OAc)n(L)16-n](M’= M-270n)

A. Cornia, et al. Angew. Chem. IE 2003, 42, 1645

16-(acetylthio)hexadecanoic acid

Mn12-bindinggroup

Au-bindinggroup

spacer

[Mn12O12(OAc)16(H2O)4] + 16RCO2H [Mn12O12(O2CR)16(H2O)4] +16AcOH

A. Cornia et al. Angew. Chem. IE 2003, 42, 1645; L. Zobbi, et al. Chem. Commun. 2005, 1640

5.0 ×××× 5.6 nm

K)8(1.55/U

s10)4(4.28

0

=

⋅=−

Bk

τ

AC-Magn. Susc.

A. Cornia, et al. Angew. Chem. IE 2003, 42, 1645

Direct Deposition on Au(111)