Synthesis, structural characterization and growth features of some (Ph)Se–Cd cluster compounds (Ph=phenyl)

Adamantane-type clusters: compounds with a ubiquitous architecture but a wide variety of compositions and unexpected materials properties

The research into adamantane-type compounds has gained momentum in recent years, yielding remarkable new applications for this class of materials. In particular, organic adamantane derivatives (AdR4) or inorganic adamantane-type compounds of the general formula [(RT)4E6] (R: organic substituent; T: group 14 atom C, Si, Ge, Sn; E: chalcogenide atom S, Se, Te, or CH2) were shown to exhibit strong nonlinear optical (NLO) properties, either second-harmonic generation (SHG) or an unprecedented type of highly-directed white-light generation (WLG) - depending on their respective crystalline or amorphous nature. The (missing) crystallinity, as well as the maximum wavelengths of the optical transitions, are controlled by the clusters' elemental composition and by the nature of the organic groups R. Very recently, it has been additionally shown that cluster cores with increased inhomogeneity, like the one in compounds [RSi{CH2Sn(E)R'}3], not only affect the chemical properties, such as increased robustness and reversible melting behaviour, but that such 'cluster glasses' form a conceptually new basis for their use in light conversion devices. These findings are likely only the tip of the iceberg, as beside elemental combinations including group 14 and group 16 elements, many more adamantane-type clusters (on the one hand) and related architectures representing extensions of adamantane-type clusters (on the other hand) are known, but have not yet been addressed in terms of their opto-electronic properties. In this review, we therefore present a survey of all known classes of adanmantane-type compounds and their respective synthetic access as well as their optical properties, if reported.

Solution and Solid-State Characterization of PbSe Precursors

The addition of lead to diphenyl diselenide in ethylenediamine (en) or pyridine (py) allowed for the observation of the solvento complexes, (en)Pb(SePh)₂ or (py)₂Pb(SePh)₂, respectively. Performing this reaction in dimethyl sulfoxide and subsequent crystallization was found to afford Pb(SePh)₂. Inductively coupled plasma optical emission spectroscopy revealed a 1:2 lead to selenium ratio for all three complexes. Nuclear magnetic resonance spectroscopy confirms that Pb(SePh)₂ is readily solubilized by ethylenediamine, and electrospray ionization mass spectrometry supports the presence of Pb(SePh)₂ moieties in solution. Single-crystal X-ray diffraction analysis of the pyridine adduct, (py)₂Pb(SePh)₂, revealed a seesaw molecular geometry featuring equatorial phenylselenolate ligands. Crystals of Pb(SePh)₂ grown from dimethyl sulfoxide revealed one-dimensional polymeric chains of Pb(SePh)₂. We believe that the lead(II) phenylselenolate complexes form via an oxidative addition reaction.

Synthesis, Characterization, Crystal Structure, and Biological Studies of a Cadmium(II) Complex with a Tridentate Ligand 4'-Chloro-2,2':6',2''-Terpyridine

A new Cd(II) complex with the ligand 4′-chloro-2,2′6′,2′′-terpyridine (Cltpy), [Cd(Cltpy)(I)₂], has been synthesized and characterized by CHN elemental analysis, ¹H-NMR, ¹³C-NMR, and IR spectroscopy and structurally analyzed by X-ray single-crystal diffraction. The single-crystal X-ray analyses show that the coordination number in complex is five with three terpyridine (Cltpy) N-donor atoms and two iodine atoms. The antibacterial activities of Cltpy and its Cd(II) complex are tested against different bacteria.