The interaction between two Ag porphyrins, connected covalently through a highly flexible ethane bridge, in a metalloporphyrin dimer has been investigated upon stepwise oxidation. X-ray structure determination of one and two-electron oxidized complexes has clearly revealed only metal-centered oxidation that results in short Ag-N (porphyrin) distance with large distortion in the porphyrin macrocycle. The 2e-oxidized complex exhibits significant metallophilic interaction in the form of a close Ag ⋅⋅⋅Ag contact that brings two porphyrin rings more cofacial with syn-conformation, which would otherwise stabilize in an anti-form. The interaction also leads to an intense emission peak at 546 nm at 77 K in the photoluminescence study.

Metallophilic interactions between closed‐shell metal ions are becoming a popular tool for a variety of applications related to high‐end materials. Heavier d8 transition‐metal ions are also considered to have a closed shell and can be involved in such interactions. There is no systematic investigation so far to estimate the structure and energy characteristics of metallophilic interactions in AgII/AgII (d9/d9), AgIII/AgIII (d8/d8), and mixed‐valent AgII/AgIII (d9/d8) complexes, which have been demonstrated in the present study. Both interporphyrinic and intermetallic interactions were investigated on stepwise oxidation by using a rigid ethene‐bridged cis silver(II) porphyrin dimer and the results compared with those for highly flexible ethane‐bridged analogues. By controlling the nature of chemical oxidants and their stoichiometry, both 1e and 2e oxidations were done stepwise to generate AgII/AgIII mixed‐valent and AgIII/AgIII porphyrin dimers, respectively. Unlike all other ethene‐bridged metalloporphyrin dimers reported earlier, in which 2e oxidation stabilizes only the trans form, such an oxidation of silver(II) porphyrin dimer stabilizes only the cis form because of the metallophilic interaction. Besides silver(II)⋅⋅⋅silver(II) interactions in cis silver(II) porphyrin dimer, stepwise oxidations also enabled us to achieve various hitherto‐unknown silver(II)⋅⋅⋅silver(III) and silver(III)⋅⋅⋅silver(III) interactions, which thereby allow significant modulation of their structure and properties. The strength of Ag⋅⋅⋅Ag interaction follows the order AgII/AgII (d9/d9)

A coumarin functionalized aminodiphosphine has been introduced as a bidentate ligand in coinage metal chemistry. Mono-, di-, and trimetallic copper and silver complexes were synthesized with this ligand. The hybrid character of the ligand led to compounds with rich luminescence properties. These include coumarin-based blue fluorescence, observed as a sole emission in solution at room temperature, and green phosphorescence, which is efficient at low temperatures and dominates the spectra of the metal complexes. In the rigid environment of frozen solutions, the green phosphorescence shows an unusually long (for metal complexes) decay on the seconds timescale in high quantum yield. In addition, a red phosphorescence, which may be assigned to the triplet state localized in the phosphine-M 3 Cl 2 (M=Cu, Ag), is observed for the trinuclear complexes at low temperature. Neither the second-long phosphorescence nor the red emission is observed for the coumarin ligand, thus they must be a result of the coordination to coinage metal clusters. The excited states in these compounds were also investigated by femtosecond transient absorption spectroscopy and quantum chemical calculations.

Fe–Li–Pb heterotrimetallic triple-decker complexes were synthesized by reduction of pentaphospha- and pentarsaferrocene with the dilithioplumbole. Both complexes comprise bent P5/As5 middle decks and plumbole as lower decks.

A family of binuclear highly substituted and distorted ferric porphyrins bridged through a variety of p-hydroquinone dianions is reported. Two iron(II) porphyrins are oxidized with a consequence of 2 e reduction of the p-benzoquinone unit, which produces the binuclear ferric complex bridged with dianions of hydroquinone. The electronic structures of the dimeric complexes have been confirmed by using UV/Vis, IR, 1 H NMR, EPR and Mössbauer spectroscopy as well as single-crystal X-ray diffraction studies. The hydroquinone plane is remarkably tilted to form a Fe-O-C angle of approximately 132°and a dihedral angle of approximately 53°with the porphyrin mean plane. Variable-temperature magnetic susceptibility measurements