skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Calix[4]arene Based Single-Molecule Magnets

Abstract

Single-molecule magnets (SMMs) have been the subject of much interest in recent years because their molecular nature and inherent physical properties allow the crossover between classical and quantum physics to be observed. The macroscopic observation of quantum phenomena - tunneling between different spin states, quantum interference between tunnel paths - not only allows scientists to study quantum mechanical laws in great detail, but also provides model systems with which to investigate the possible implementation of spin-based solid state qubits and molecular spintronics. The isolation of small, simple SMMs is therefore an exciting prospect. To date almost all SMMs have been made via the self-assembly of 3d metal ions in the presence of bridging/chelating organic ligands. However, very recently an exciting new class of SMMs, based on 3d metal clusters (or single lanthanide ions) housed within polyoxometalates, has appeared. These types of molecule, in which the SMM is completely encapsulated within (or shrouded by) a 'protective' organic or inorganic sheath have much potential for design and manipulation: for example, for the removal of unwanted dipolar interactions, the introduction of redox activity, or to simply aid functionalization for surface grafting. Calix[4]arenes are cyclic (typically bowl-shaped) polyphenols that have been used extensively inmore » the formation of versatile self-assembled supramolecular structures. Although many have been reported, p-{sup t}But-calix[4]arene and calix[4]arene (TBC4 and C4 respectively, Figure 1A) are frequently encountered due to (a) synthetic accessibility, and (b) vast potential for alteration at either the upper or lower rim of the macrocyclic framework. Within the field of supramolecular chemistry, TBC4 is well known for interesting polymorphic behavior and phase transformations within anti-parallel bi-layer arrays, while C4 often forms self-included trimers. The polyphenolic nature of calix[n]arenes (where n = 4-8) also suggests they should be excellent candidates as ligands for the isolation of molecular magnets, but to date their use in the isolation of paramagnetic cluster compounds is rather limited. Herein we present the first Mn cluster and the first SMM to be isolated using any methylene bridged calix[n]arene - a ferromagnetically coupled mixed-valence [Mn{sub 2}{sup III}Mn{sub 2}{sup II}] complex housed between either two TBC4s or two C4s.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
Advanced Light Source Division
OSTI Identifier:
984962
Report Number(s):
LBNL-3608E
Journal ID: ISSN 0044-8249; ISSN 1521-3757; TRN: US201016%%1688
DOE Contract Number:  
DE-AC02-05CH11231
Resource Type:
Journal Article
Journal Name:
Angewandte Chemie
Additional Journal Information:
Journal Volume: 121; Journal Issue: 44; Related Information: Journal Publication Date: 2009; Journal ID: ISSN 0044-8249
Country of Publication:
United States
Language:
English
Subject:
37; CHEMISTRY; DESIGN; IMPLEMENTATION; MAGNETS; PHASE TRANSFORMATIONS; PHYSICAL PROPERTIES; PHYSICS; POLYPHENOLS; QUBITS; RARE EARTHS; REMOVAL; SPIN; TUNNELING

Citation Formats

Karotsis, Georgios, Teat, Simon J, Wernsdorfer, Wolfgang, Piligkos, Stergios, Dalgarno, Scott J, and Brechin, Euan K. Calix[4]arene Based Single-Molecule Magnets. United States: N. p., 2009. Web. doi:10.1002/ange.200904094.
Karotsis, Georgios, Teat, Simon J, Wernsdorfer, Wolfgang, Piligkos, Stergios, Dalgarno, Scott J, & Brechin, Euan K. Calix[4]arene Based Single-Molecule Magnets. United States. doi:10.1002/ange.200904094.
Karotsis, Georgios, Teat, Simon J, Wernsdorfer, Wolfgang, Piligkos, Stergios, Dalgarno, Scott J, and Brechin, Euan K. Thu . "Calix[4]arene Based Single-Molecule Magnets". United States. doi:10.1002/ange.200904094. https://www.osti.gov/servlets/purl/984962.
@article{osti_984962,
title = {Calix[4]arene Based Single-Molecule Magnets},
author = {Karotsis, Georgios and Teat, Simon J and Wernsdorfer, Wolfgang and Piligkos, Stergios and Dalgarno, Scott J and Brechin, Euan K},
abstractNote = {Single-molecule magnets (SMMs) have been the subject of much interest in recent years because their molecular nature and inherent physical properties allow the crossover between classical and quantum physics to be observed. The macroscopic observation of quantum phenomena - tunneling between different spin states, quantum interference between tunnel paths - not only allows scientists to study quantum mechanical laws in great detail, but also provides model systems with which to investigate the possible implementation of spin-based solid state qubits and molecular spintronics. The isolation of small, simple SMMs is therefore an exciting prospect. To date almost all SMMs have been made via the self-assembly of 3d metal ions in the presence of bridging/chelating organic ligands. However, very recently an exciting new class of SMMs, based on 3d metal clusters (or single lanthanide ions) housed within polyoxometalates, has appeared. These types of molecule, in which the SMM is completely encapsulated within (or shrouded by) a 'protective' organic or inorganic sheath have much potential for design and manipulation: for example, for the removal of unwanted dipolar interactions, the introduction of redox activity, or to simply aid functionalization for surface grafting. Calix[4]arenes are cyclic (typically bowl-shaped) polyphenols that have been used extensively in the formation of versatile self-assembled supramolecular structures. Although many have been reported, p-{sup t}But-calix[4]arene and calix[4]arene (TBC4 and C4 respectively, Figure 1A) are frequently encountered due to (a) synthetic accessibility, and (b) vast potential for alteration at either the upper or lower rim of the macrocyclic framework. Within the field of supramolecular chemistry, TBC4 is well known for interesting polymorphic behavior and phase transformations within anti-parallel bi-layer arrays, while C4 often forms self-included trimers. The polyphenolic nature of calix[n]arenes (where n = 4-8) also suggests they should be excellent candidates as ligands for the isolation of molecular magnets, but to date their use in the isolation of paramagnetic cluster compounds is rather limited. Herein we present the first Mn cluster and the first SMM to be isolated using any methylene bridged calix[n]arene - a ferromagnetically coupled mixed-valence [Mn{sub 2}{sup III}Mn{sub 2}{sup II}] complex housed between either two TBC4s or two C4s.},
doi = {10.1002/ange.200904094},
journal = {Angewandte Chemie},
issn = {0044-8249},
number = 44,
volume = 121,
place = {United States},
year = {2009},
month = {6}
}