TY - JOUR

T1 - LnDOTA puppeteering

T2 - removing the water molecule and imposing tetragonal symmetry

AU - Manvell, Anna Schannong

AU - Pfleger, Rouven

AU - Bonde, Niels Andreas

AU - Briganti, Matteo

AU - Mattei, Carlo Andrea

AU - Nannestad, Theis Brock

AU - Weihe, Høgni

AU - Powell, Annie K.

AU - Ollivier, Jacques

AU - Bendix, Jesper

AU - Perfetti, Mauro

N1 - Funding Information: Funded by the European Union (ERC, ELECTRA, 101039890). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. The financial support provided by the MUR – Dipartimenti di Eccellenza 2023-2027 (DICUS 2.0) to the Department of Chemistry “Ugo Schiff” of the University of Florence is acknowledged. RP and AKP acknowledge the Karlsruhe House of Young Scientists (KHYS) for the Research Travel Grant and the Networking Grant and the German Research Foundation (DFG) Collaborative Research Centre (CRC) 1573 "4f for Future". Funding Information: Funded by the European Union (ERC, ELECTRA, 101039890). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. The financial support provided by the MUR - Dipartimenti di Eccellenza 2023-2027 (DICUS 2.0) to the Department of Chemistry “Ugo Schiff” of the University of Florence is acknowledged. RP and AKP acknowledge the Karlsruhe House of Young Scientists (KHYS) for the Research Travel Grant and the Networking Grant and the German Research Foundation (DFG) Collaborative Research Centre (CRC) 1573 "4f for Future". Publisher Copyright: © 2024 The Royal Society of Chemistry.

PY - 2023/12/12

Y1 - 2023/12/12

N2 - Complexes of lanthanide(iii) ions (Ln) with tetraazacyclododecane-N,N′,N′′,N′′′-tetraacetate (DOTA) are a benchmark in the field of magnetism due to their well-investigated and sometimes surprising features. Ab initio calculations suggest that the ninth ligand, an axial water molecule, is key in defining the magnetic properties because it breaks the potential C4 symmetry of the resulting complexes. In this paper, we experimentally isolate the role of the water molecule by excluding it from the metal coordination sphere without altering the chemical structure of the ligand. Our complexes are therefore designed to be geometrically tetragonal and strict crystallographic symmetry is achieved by exploiting a combination of solution ionic strength and solid state packing effects. A thorough multitechnique approach has been used to unravel the electronic structure and magnetic anisotropy of the complexes. Moreover, the geometry enhancement allows us to predict, using only one angle obtained from the crystal structure, the ground state composition of all the studied derivatives (Ln = Tb to Yb). Therefore, these systems also provide an excellent platform to test the validity and limitations of the ab initio methods. Our combined experimental and theoretical investigation proves that the water molecule is indeed key in defining the magnetic anisotropy and the slow relaxation of these complexes.

AB - Complexes of lanthanide(iii) ions (Ln) with tetraazacyclododecane-N,N′,N′′,N′′′-tetraacetate (DOTA) are a benchmark in the field of magnetism due to their well-investigated and sometimes surprising features. Ab initio calculations suggest that the ninth ligand, an axial water molecule, is key in defining the magnetic properties because it breaks the potential C4 symmetry of the resulting complexes. In this paper, we experimentally isolate the role of the water molecule by excluding it from the metal coordination sphere without altering the chemical structure of the ligand. Our complexes are therefore designed to be geometrically tetragonal and strict crystallographic symmetry is achieved by exploiting a combination of solution ionic strength and solid state packing effects. A thorough multitechnique approach has been used to unravel the electronic structure and magnetic anisotropy of the complexes. Moreover, the geometry enhancement allows us to predict, using only one angle obtained from the crystal structure, the ground state composition of all the studied derivatives (Ln = Tb to Yb). Therefore, these systems also provide an excellent platform to test the validity and limitations of the ab initio methods. Our combined experimental and theoretical investigation proves that the water molecule is indeed key in defining the magnetic anisotropy and the slow relaxation of these complexes.

U2 - 10.1039/d3sc03928e

DO - 10.1039/d3sc03928e

M3 - Journal article

C2 - 38131074

AN - SCOPUS:85179787179

VL - 15

SP - 113

EP - 123

JO - Chemical Science

JF - Chemical Science

SN - 2041-6520

IS - 1

ER -