A series of Cu(I) complexes with a [Cu(NN)(PP)](+) moiety, [Cu(phen)(pba)](BF(4)) (1a), [Cu(2)(phen)(2)(pbaa)](BF(4))(2) (2a), [Cu(2)(phen)(2)(pnaa)](BF(4))(2) (3a), [Cu(2)(phen)(2)(pbbaa)](BF(4))(2) (4a), [Cu(dmp)(pba)](BF(4)) (1b), [Cu(2)(dmp)(2)(pbaa)](BF(4))(2) (2b), [Cu(2)(dmp)(2)(pnaa)](BF(4))(2) (3b) and [Cu(2)(dmp)(2)(pbbaa)](BF(4))(2) (4b) (phen = 1,10-phenanthroline, dmp = 2,9-dimethyl-1,10-phenanthroline, pba = N,N-bis((diphenylphosphino)methyl)benzenamine, pbaa = N,N,N',N'-tetrakis((diphenylphosphino)methyl)benzene-1,4-diamine, pnaa = N,N,N',N'-tetrakis((diphenylphosphino)methyl)naphthalene-1,5-diamine and pbbaa = N,N,N',N'-tetrakis((diphenylphosphino)methyl)biphenyl-4,4'-diamine), were rationally designed and synthesized. These complexes were characterized by (1)H and (31)P NMR, electrospray mass spectrometry, elemental analysis and X-ray crystal structure analysis. Introduction of different central arene spacers (phenyl, naphthyl, biphenyl) into ligands, resulting in the size variation of these complexes, aims to tune the photophysical properties of the complexes. Each Cu(I) ion in these complexes adopts a distorted tetrahedral geometry constructed by the chelating diimine and phosphine groups. Intermolecular C-H···π and/or π···π interactions are involved in the solid states. The dmp-containing complex exhibits better emission relative to the corresponding phen complex due to the steric encumbrance of bulky alkyl groups. Furthermore, for complexes with identical diimine but different phosphine ligands, the tendency of increased emission lifetime as well as blue-shifted emission in the solid state follows with the decrease in size of complexes. Intermolecular C-H···π interactions have an influence on the final solid state photophysical properties through vibrationally relaxed non-radiative energy transfer in the excited state. Smaller-sized complexes show better photophysical properties due to less vibrationally relaxed behavior related to flexible C-H···π bonds. Nevertheless, the tendency for increased quantum yield and emission lifetime, as well as blue-shifted emission in dilute solution goes with the increase in size of complexes. The central arene ring (phenyl, naphthyl or biphenyl) has an influence on the final photophysical properties. The larger the π-conjugated extension of central arene ring is, the better the photophysical properties of complex are. The rigid and large-sized complex 3b, with a high quantum yield and long lifetime, is the best luminophore among these complexes.

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A discrete tetrahedral indium cage, {[In 12 (μ 3 -OH) 4 (HCO 2 ) 24 (tcma) 4 ]} (In 12 -GL), was synthesized solvothermally by the reaction of indium nitrate with the tripodal tricarboxylic acid ligand N,N,N-tris{(2′-carboxy[1,1′-biphenyl]-4yl)methyl}methylammonium chloride ([H 3 tcma] + Cl). This cage consists of four trimeric units [In 3 (μ 3 -OH)(μ 2 -CO 2 ) 3 (μ 2 -HCO 2 ) 3 ] and four [tcma] 2− ligands, which all perform as 3-connection nodes to bridge each other, resulting in a tetrahedral cage structure. The trimeric unit [In 3 (μ 3 -OH)(μ 2 -CO 2 ) 3 (μ 2 -HCO 2 ) 3 ] is observed for the first time in the family of In-based metal−organic structures and can be considered as an evolution of a 6-connected [In 3 (μ 3 -O)(μ 2 -CO 2 ) 6 ] unit. Each In 3+ is terminally coordinated by a μ 1 -HCO 2 group. This cage contains potential Lewis acidic/basic active sites endowed by In 3+ ions as Lewis acidic sites and the uncoordinated oxygen atoms of μ 1 -HCO 2 moieties as Lewis basic sites and was explored as an effective heterogeneous catalyst in the cycloaddition of CO 2 with epoxides and the Strecker reaction for amino nitriles. These catalytic reactions were deduced to happen on the surface of the In 12 -GL cage.

The controlling synthesis of novel nanoclusters of noble metals (Au, Ag) and the determination of their atomically precise structures provide opportunities for investigating their specific properties and applications. Here we report a novel silver nanocluster [Ag307Cl62(SPh t Bu)110] (Ag307) whose structure is determined by X-ray single crystal diffraction. The structure analysis shows that nanocluster Ag307 contains a Ag167 core, a surface shell of [Ag140Cl2S110], and a Cl60 intermediate layer located between Ag167 and [Ag140Cl2S110]. It is a first example that such many chlorides are intercalated into a Ag nanocluster. Chlorides are released in situ from solvent CHCl3. Nanocluster Ag307 exhibits superstability. Differential pulse voltammetry experiment reveals that Ag307 has continuous charging/discharging behavior with a capacitance value of 1.39 aF, while the Ag307 has a surface plasmonic feature. These characteristics show that Ag307 is of metallic behavior. However, its electron paramagnetic resonance (EPR) spectra display a spin magnetic behavior which could be originated from the unpassivated dangling bonds of surface atoms. The direct capture of EPR signals can be attributed to the Cl– intercalating layer which partly suppresses the electronic interactions between core and surface atoms, resulting in the relatively independent electronic states for core and surface atoms.

A first and stable Ag-P superatom nanocluster [Ag(N-triphos)(Cl)](NO) (1) has been successfully synthesized and characterized. X-ray analysis shows that this Ag cluster has a hexacapped body-centered cubic (bcc) framework which is consolidated by four tripodal N-triphos ligands. The identity of 1 is confirmed by high resolution ESI-MS. Cluster 1 has an electronic and geometric shell closure structure with 8 free electrons, matching the stability idea of superatom theory for a nanocluster. DFT calculation of this Ag cluster reveals the superatom feature with a 1S1P configuration. The chelation of multidentate phosphines enhances the stability of this Ag cluster. The AgAg distances between the centered and the vertical Ag atoms of this bcc (Ag@Ag) are in the range of 2.57-2.71 Å, and the distances between the face-capped and the vertical silver atoms are in the range of 2.84-2.92 Å, showing strong AgAg interactions within this cluster core. This superatom complex exhibits a relatively high thermal and photolytic stability.