Pt as Mediator of Strong Antiferromagnetic Coupling between Two CuII Ions in a Heteronuclear CuIIPtIICuII Complex of the Model Nucleobase 1-Methylcytosinate

Hegmans, Alexander; Zangrando, Ennio; Freisinger, Eva; Pichierri, Fabio; Randaccio, Lucio; Mealli, Carlo; Gerdan, Michael; Trautwein, Alfred X.; Lippert, Bernhard

doi:10.1002/(sici)1521-3765(19991001)5:10<3010::aid-chem3010>3.0.co;2-o

Cited by 29 publications

(7 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The strongest magnetic interactions are observed in [Co 2 PdCl 2 (dpa) 4 ] (dpa = bis(2-pyridyl)amide), where Co ions are bridged by a Pd ion to be Co–Pd–Co with a separation of 5.0 Å. In this compound, the stronger interaction is attributed to the central Pd ion acting as a spacer but not as a spectator for attenuating the electronic communication between two termini, , believing that the second metal mediation is superior to organic molecules or halogen bridges for stronger magnetic interaction. Although 3 has a weaker magnetic interaction than this compound, 3 shows a large value (−22.2 cm –1 ) for the distance (13.3 Å) between Co ions.…”

Section: Resultsmentioning

confidence: 94%

“…The study of heterometallic complexes continually leads researchers toward new compound creation by the combination of metallic species to afford diverse structural, electronic, magnetic properties, and catalytic activity. − Among these new compounds, heteronuclear metal string complexes (HMSCs), where two or three metals are regularly aligned as several strings with metal–metal bonds, have been the focus of attention due to their potential applications, which are not found in extended metal atom chains comprised of homometals. , For example, an asymmetric pentanuclear complex aligned as Ni–Ru–Ru–Ni–Ni shows a negative differential resistance expecting a molecular rectifier, and a heterotrimetallic complex aligned as Mo–Mo–Ni shows an extraordinarily large ferromagnetic coupling thorough metal–metal bonds, which are attributed to abnormal electronic structures induced by connecting multiple metals. Several HMSCs, − as well as pioneered heterometallic complexes, − have been reported. Rational and systematic synthesis methods are currently being explored and sequential synthesis methods for trinuclear complexes are suggested …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Paramagnetic One-Dimensional Chain Complex Consisting of Three Kinds of Metallic Species Showing Magnetic Interaction through Metal–Metal Bonds

Uemura

Miyake

2019

Inorg. Chem.

View full text Add to dashboard Cite

A heterometallic and paramagnetic one-dimensional (1-D) chain (3) aligned as −Rh(+2)−Rh(+2)− Pt(+2)−Co(+2)−Pt(+2)− with direct metal−metal bonds was obtained by HOMO−LUMO interactions at the σ* (d z 2 ) orbital between two kinds of complexes. The 1-D chains in 3 have relatively straight backbones because the raw material complexes, [Rh 2 (O 2 CCH 3 ) 4 ] and [Pt 2 Co(piam) 4 (NH 3 ) 4 ], are connected and stacked in a face-to-face fashion, where Co---Co are separated by about 13.3 Å with four different metals.Physical measurements revealed that 3 has a band gap between the σ-type conduction and valence bands, where dorbitals of the Co ion with three unpaired electrons are laid among them. The magnetic behavior of 3 was investigated and found to be consistent with a complex interaction involving both zero-field splitting and Pauli paramagnetism attributed to band formation superimposed on relatively strong exchange coupling (zJ = −22.2 cm −1 ) between two high-spin Co(+2) ions separated by the diamagnetic Pt−Rh−Rh−Pt.

show abstract

Section: Resultsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Paramagnetic One-Dimensional Chain Complex Consisting of Three Kinds of Metallic Species Showing Magnetic Interaction through Metal–Metal Bonds

Uemura

Miyake

2019

Inorg. Chem.

View full text Add to dashboard Cite

show abstract

“…Lippert and co-workers introduced paramagnetic heterometallic metal–metal bonded chains in 1981 . Their synthetic strategy was to use Pt II –nucleobase complexes as metalloligands, producing a wide variety of Pt–M–Pt heterotrimetallic compounds having paramagnetic central M atoms. − For example, the methylthymine complex with a central Pd III ion is shown in Figure . Analysis of the electronic transitions and EPR spectra of these compounds led to the conclusion that the filled Pt d z 2 orbitals act as ligands to the central metal atom .…”

Section: Introduction and Overviewmentioning

confidence: 64%

“…Another related trimetallic species with a Cu 2 Pt core was supported by the 1-methylcytosinate ligand. The diamagnetism of the compound stems from strong antiferromagnetic coupling between the two Cu II ions mediated by the central Pt II d z 2 orbital …”

Section: Introduction and Overviewmentioning

confidence: 99%

Paramagnetic Metal–Metal Bonded Heterometallic Complexes

2020

View full text Add to dashboard Cite

Significant progress has been made in the past 10–15 years on the design, synthesis, and properties of multimetallic coordination complexes with heterometallic metal–metal bonds that are paramagnetic. Several general classes have been explored including heterobimetallic compounds, heterotrimetallic compounds of either linear or triangular geometry, discrete molecular compounds containing a linear array of more than three metal atoms, and coordination polymers with a heterometallic metal–metal bonded backbone. We focus in this Review on the synthetic methods employed to access these compounds, their structural features, magnetic properties, and electronic structure. Regarding the metal–metal bond distances, we make use of the formal shortness ratio (FSR) for comparison of bond distances between a broad range of metal atoms of different sizes. The magnetic properties of these compounds can be described using an extension of the Goodenough–Kanamori rules to cases where two magnetic ions interact via a third metal atom. In describing the electronic structure, we focus on the ability (or not) of electrons to be delocalized across heterometallic bonds, allowing for rationalizations and predictions of single-molecule conductance measurements in paramagnetic heterometallic molecular wires.

show abstract

“…Theoretical calculations for the electronic structures of complexes with metal–metal bonds made it possible to analyze the influence of different ligands and the metal–metal lengths on the characteristics of molecular orbitals (MOs) and to determine the MOs energies and populations. ,,− In short words the metal–metal bond can be understood as the result of the d-orbitals superposition achieving σ (d z 2 ), π (d xz , d yz ) and δ (d xy , d x 2 – y 2 ) bonding and antibonding type of orbitals which population determines the metal–metal bond order. Particularly heterobimetallic complexes where metal–metal bond is established between two different metals represent a special group of compounds which combine the attractive physical properties that arise from metal–metal bonding, such has conductivity and magnetic communication, with the ability to incorporate the electronic anisotropy resulting from different metal centers in communication. − The existence of the metal–metal bond between paramagnetic and diamagnetic metal centers has allowed the design and synthesis of 1D materials with different applications and particularly, in the field of molecular magnetism, this kind of complexes are building blocks whose electronic and magnetic properties can be modulated with the correct selection of the ligand arrangement. ,− …”

Section: Introductionmentioning

confidence: 99%

Antiferromagnetic Coupling Supported by Metallophilic Interactions: Theoretical View

2022

View full text Add to dashboard Cite

The antiferromagnetic coupling supported by metallophilic interactions has been studied in the framework of the broken symmetry approach (BS) and multiconfigurational calculations (CASSCF). A series of heterobimetallic complexes of the form [PtCo(X) 4 (Y)] 2 (X = tba thiobenzoate, SAc thioacetate, and Y = H 2 O, NO 2 py, py), previously reported, have been used as model systems. Magnetic coupling constants were found in good agreement with the experimental reports, and it could be concluded that axial ligands with a pure σ-donor character have a marked effect on the J value strengthening the antiferromagnetic coupling, as shown for [PtCo-(SAc) 4 (H 2 O)] 2 and [PtNi(SAc) 4 (H 2 O)] 2 . The latter complex, included for comparative purposes, also made it possible to evidence that the interaction between magnetic orbitals and low-level excitation in the Pt•••Pt region is also relevant favoring the stronger antiferromagnetic coupling found in this case. A careful analysis of the energetic components involved in Pt•••Pt interaction suggests that the stabilization arises from a combination of favorable orbital contributions, which allows a weak covalent Pt•••Pt σ(dz 2 ...dz 2 ) bond. Theoretical tools evidence that the weak σ-bond found between monomeric units is responsible for a spin polarization mechanism resulting in the observed antiferromagnetic interaction. Multiconfigurational calculations finally allowed us to establish that the spin polarization mechanism involves not only the d z 2 orbitals in the M-Pt•••Pt-M bond direction but also the empty 6p z orbitals of Pt atoms. The inclusion of these orbitals favors a correlation-induced delocalization of magnetic orbitals and therefore a better balance among direct and kinetic exchange. The results shown in this work are relevant in the molecular design of systems supported by metallophilic interactions not only between platinum atoms but also could be extended to other cases with similar interactions.

show abstract

Pt as Mediator of Strong Antiferromagnetic Coupling between Two CuII Ions in a Heteronuclear CuIIPtIICuII Complex of the Model Nucleobase 1-Methylcytosinate

Cited by 29 publications

References 18 publications

Paramagnetic One-Dimensional Chain Complex Consisting of Three Kinds of Metallic Species Showing Magnetic Interaction through Metal–Metal Bonds

Paramagnetic One-Dimensional Chain Complex Consisting of Three Kinds of Metallic Species Showing Magnetic Interaction through Metal–Metal Bonds

Paramagnetic Metal–Metal Bonded Heterometallic Complexes

Antiferromagnetic Coupling Supported by Metallophilic Interactions: Theoretical View

Contact Info

Product

Resources

About