Dalton Transactions

doi: 10.1039/d4dt90084gpmid: N/A

doi: 10.1039/d4dt90085epmid: N/A

doi: 10.1039/d4dt90086cpmid: N/A

Tanaka, Yuya

doi: 10.1039/d4dt00668bpmid: 38712999

Molecular junctions, which involve sandwiching molecular structures between electrodes, play a crucial role in molecular electronics. Recent advances in this field have revealed the vital role of organometallic chemistry in the investigation of molecular junctions, which has added to their well-known contributions to catalysis and materials chemistry. This review summarizes the recent examples of organometallic chemistry applications in molecular junctions, which can be categorized into three types, i.e., class I encompassing molecular junctions with bridging organometallic complexes, class II involving molecular junctions with covalent and noncovalent metal electrode-carbon bonds, and class III comprising organometallic reactions within molecular junctions.

Wenger, John S.; Johnstone, Timothy C.

doi: 10.1039/d4dt00506fpmid: 38717258

The elucidation of novel bonding situations at heavy p-block elements has greatly advanced recent efforts to access useful reactivity at earth-abundant main-group elements. Molecules with unsaturated bonds between heavier, electropositive elements and lighter, electronegative elements are often highly polarized and competent in small-molecule activations, but the reactivity of these molecules may be quenched by self-association of monomers to form oligomeric species where the polar, unsaturated groups are assembled in a head-to-tail fashion. In this Frontier, we discuss the synthetic strategies employed to isolate monomeric σ2,λ3-stibinidene chalcogenides (RSbCh) and monomeric σ4,λ5-stibine chalcogenides (R3SbCh). These classes of molecules each feature polarized antimony–chalcogenide bonds (Sb = Ch/Sb+–Ch−). We highlight how the synthesis and isolation of these molecules has led to the discovery of novel reactivity and has shed light on fundamental aspects of inorganic structure and bonding. Despite these advances, there are critical aspects of this chemistry that remain underdeveloped and we provide our perspective on yet-unrealized synthetic targets that may be achieved with the continued development of the strategies described herein.

Ferraro, Giarita; Lyčková, Tereza; Massai, Lara; Štarha, Pavel; Messori, Luigi; Merlino, Antonello

doi: 10.1039/d4dt00773epmid: 38727007

The reactivity of the anticancer drug picoplatin (cis-amminedichlorido(2-methylpyridine)platinum(ii) complex) with the model proteins hen egg white lysozyme (HEWL) and bovine pancreatic ribonuclease (RNase A) was investigated by electrospray ionisation mass spectrometry (ESI MS) and X-ray crystallography. The data were compared with those previously obtained for the adducts of these proteins with cisplatin, carboplatin and oxaliplatin under the same experimental conditions. ESI-MS data show binding of Pt to both proteins, with fragments retaining the 2-methylpyridine ligand and, possibly, a chloride ion. X-ray crystallography identifies different binding sites on the two proteins, highlighting a different behaviour of picoplatin in the absence or presence of dimethyl sulfoxide (DMSO). Metal-containing fragments bind to HEWL close to the side chains of His15, Asp18, Asp119 and both Lys1 and Glu7, whereas they bind to RNase A on the side chain of His12, Met29, His48, Asp53, Met79, His105 and His119. The data suggest that the presence of DMSO favours the loss of 2-methylpyridine and alters the ability of the Pt compound to bind to the two proteins. With both proteins, picoplatin appears to behave similarly to cisplatin and carboplatin when dissolved in DMSO, whereas it behaves more like oxaliplatin in the absence of the coordinating solvent. This study provides important insights into the pharmacological profile of picoplatin and supports the conclusion that coordinating solvents should not be used to evaluate the biological activities of Pt-based drugs.

Uhlig, Felix; Stammler, Michael B.; Meurer, Florian; Shenderovich, Ilya G.; Blahut, Jan; Wisser, Florian M.

doi: 10.1039/d4dt01273apmid: 38712528

The structural features of cobalt-based oxygen evolution catalysts are elucidated by combining high-field MAS NMR spectroscopy and DFT calculations. The superior photocatalytic activity of the heterogeneous system over its homogeneous counterpart is rationalised by the structural features. The higher activity is caused by a more favourable electron-withdrawing character of the framework.

Tsurugi, Hayato; Mori, Hiroki; Mori, Haruna; Nakamoto, Masami; Tanaka, Shinji; Mashima, Kazushi

doi: 10.1039/d4dt00932kpmid: 38712880

The Lewis basicity of a μ3-oxo ligand for (μ3-O)[Rh(cod)]3(μ4-O)M (cod = 1,5-cyclooctadiene) complexes was controllable by metal species on the μ4-oxo ligand locating at the opposite site of the μ3-oxo ligand. Coordination of the μ3-oxo ligand of [(μ3-O){Rh(cod)}3(μ4-O){Au(PPh3)}][BF4] (1) to [Au(PPh3)]+ indicated sufficient Lewis basicity of the μ3-oxo ligand in 1 to form [{(Ph3P)Au}(μ3-O){Rh(cod)}3(μ4-O){Au(PPh3)}][BF4] (2). In contrast, the addition of Li+ to 1 induced elimination of the originally coordinated [Au(PPh3)]+ due to the weak Lewis basicity of the μ3-oxo ligand for (μ3-O){Rh(cod)}3(μ4-O)Li(THF)3, in which a pentanuclear species, [{(Ph3P)Au}(μ3-O){Rh(cod)}3(μ4-O){Li(THF)3}][BF4] (3), was assumed to be generated in situ before the dissociation of [Au(PPh3)]+.

Cabrera-Lobera, Natalia; del Horno, Estefanía; Quirós, M. Teresa; Buñuel, Elena; Gimeno, Magali; Brennessel, William W.; Neidig, Michael L.; Priego, José Luis; Cárdenas, Diego J.

doi: 10.1039/d3dt04247bpmid: 38715455

We have synthesised and characterised the complex Ni(tpy)2 (tpy = 2,2′:6′,2′′-terpyridine). This formally Ni(0) complex is paramagnetic both in the solid state and in solution (S = 2). The crystal structure shows an octahedral geometry, with molecules arranged in independent dimers involving π-stacking between pairs of complexes. Magnetic measurementes and DFT calculations suggest the existence of temperature-dependent intermolecular antiferromagnetic coupling in the solid state.

Inage, Kota; Wang, Mengfei; Hasegawa, Yasuchika; Kitagawa, Yuichi

doi: 10.1039/d4dt00286epmid: 38567493

Photosensitizer design of luminescent terbium (Tb(iii)) complexes with narrow bandwidths is important for advancing luminescent materials. In this study, we report an effective photosensitizer model in a thermally populated lowest excited triplet (T1) state during Tb(iii) emission. The Tb(iii) complex comprises a Tb(iii) ion (serving as an emission center), hexafluoroacetylacetonates (acting as photosensitizer ligands), and bulky cyclohexyl group-attached phosphine-oxide-type ligands (functioning as an oxygen barrier system). Emission properties including emission and excitation spectra, ligand-excited emission quantum yields, and emission lifetimes were evaluated in the absence and presence of oxygen. Coordination geometry structures were determined through analysing single-crystal structures. The electronic structure based on 4f-orbitals was estimated from radiative rate constants and quantum chemical calculations. The bulky phosphine oxide ligand not only provides an oxygen barrier system but also induces an electronic structural modulation based on 4f-orbitals, allowing for effective photosensitized Tb(iii) emission in a thermally populated ligand T1 state in air.