From single atoms to self-assembled quantum single-atomic nanowires: noble metal atoms on black phosphorene monolayers.

Transition metal (TM) nanostructures, such as one dimensional (1D) nanowires with/without substrates, usually possess drastically different properties from their bulk counterparts, due to their distinct stacking and electronic confinement. Correspondingly, it is of great importance to establish the dominant driving force in forming 1D single-metal-atom-wires (SMAWs). Here, with first-principles calculations, taking the black phosphorene (BP) monolayer as a prototype 2D substrate, we investigate the energetic and kinetic properties of all the 5d-TM atoms on the 2D substrate to reveal the mechanism of formation of SMAWs. In contrast to other 5d- and 4d-TMs, noble metal elements Pd and Pt are found to prefer to grow along the trough in an atom-by-atom manner, self-assembling into SMAWs with a significant magic growth behavior. This is due to distinct binding energies and diffusion barriers along the trough, i.e., zig-zag direction, as compared to other directions of the BP. The present findings are valuable in the fabrication and modulation of 1D nanostructures which can be anticipated to possess desirable functionalities for potential applications such as in nanocatalysis, nanosensors, and related areas.

1-(2-Fluoro-benz-yl)quinolinium bis-(2-sulfanylidene-1,3-dithiole-4,5-dithiol-ato-κS,S')nickelate(III).

The crystal structure of the title compound, (C(16)H(13)FN)[Ni(C(3)S(5))(2)], consists of Ni(III) complex anions and 1-(2-fluoro-benz-yl)quinolinium (fbq) cations. In the complex anion, the Ni(III) cation is chelated by two 2-sulfanylidene-1,3-dithiole-4,5-dithiol-ate (dmit) dianions in a distorted square-planar geometry; the two dmit mean planes are twisted with respect to each other at a dihedral angle of 8.44 (3)°. In the fbq cation, the dihedral angle between the benzene ring and the quinoline ring system is 80.57 (14)°. The centroid-centroid distance of 3.860 (5) Šbetween benzene rings indicates π-π stacking between adjacent fbq cations. The distance of 3.4958 (18) Šbetween the S atom and the centroid of the pyridine ring suggests the existence of a lone-pair-aromatic inter-action between the anion and the cation. A short S⋯S contact [3.387 (2) Å] is also observed in the crystal structure.

Poly[bis[µ-1,3-bis-(imidazol-1-ylmeth-yl)benzene-κN:N]bis-(nitrato-κO)cadmium].

A novel metal-organic framework based on 1,3-bis-(imidazol-1-ylmeth-yl)benzene (1,3-bimb), [Cd(NO(3))(2)(C(14)H(14)N(4))(2)](n), has been synthesized hydro-thermally. The structure exhibits a two-dimensional metal-organic (4,4)-net composed of Cd(II) atoms and bimb ligands, and such layers are further joined through inter-layer C-H⋯O hydrogen bonds to generate a three-dimensional supra-molecular structure.

Poly[[hexa-aqua-bis-(µ(3)-benzene-1,3,5-tricarboxyl-ato-κO:O:O)bis-(5,5'-dimethyl-2,2'-bipyridine-κN,N')trizinc] hexa-hydrate].

In the title compound, {[Zn(3)(C(9)H(3)O(6))(2)(C(12)H(12)N(2))(2)(H(2)O)(6)]·6H(2)O}(n), one Zn(II) atom, lying on an inversion center, is six-coordinated by two O atoms from two benzene-1,3,5-tricarboxyl-ate (btc) ligands and four water mol-ecules in a distorted octa-hedral geometry. The other Zn(II) atom is five-coordinated by two N atoms from a 5,5'-dimethyl-2,2'-bipyridine (dmbpy) ligand, two O atoms from two btc ligands and one water mol-ecule in a distorted trigonal-bipyramidal geometry. The compound features a one-dimensional ladder structure, with windows of ca 10.245 (1) × 15.446 (2) Å. The ladders are linked together by inter-molecular O-H⋯O hydrogen bonds and π-π inter-actions between the benzene rings and between the pyridine rings [centroid-to-centroid distances 3.858 (2) and 3.911 (3) Å, respectively] to form a three-dimensional supra-molecular structure. One of the lattice water molecules is disordered over two positions in a 0.592:0.408 ratio.

Diaqua-(5-carb-oxy-benzene-1,3-di-carboxyl-ato-κO)(4,4'-dimethyl-2,2'-bipyridine-κN,N')zinc.

In the title compound, [Zn(C(9)H(4)O(6))(C(12)H(12)N(2))(H(2)O)(2)], the Zn(II) atom is five-coordinated by two N atoms from a 4,4'-dimethyl-2,2'-bipyridine ligand, one O atom from a 5-carb-oxy-benzene-1,3-dicarboxyl-ate ligand and two water mol-ecules in a distorted trigonal-bipyramidal geometry. The complex mol-ecules are linked by inter-molecular O-H⋯O hydrogen bonds and partly overlapping π-π inter-actions [centroid-centroid distance = 4.017 (2) Å] into a three-dimensional supra-molecular network.

Poly[bis-[µ-1,4-bis-(imidazol-1-ylmeth-yl)benzene]-dichloridomanganese(II)].

In the crystal structure of the title compound, [MnCl(2)(C(14)H(14)N(4))(2)](n), the Mn(II) atom, lying on an inversion center, is coordinated by four N atoms from four 1,4-bis-(imidazol-1-ylmeth-yl)benzene (bimb) ligands and two Cl(-) anions in a distorted octa-hedral geometry. The bimb ligands bridge the Mn(II) atoms, forming a two-dimensional polymeric complex, which is composed of a 52-membered [Mn(4)(bimb)(4)] ring with distances of 7.7812 (2) and 27.4731 (9) Šbetween opposite metal atoms. Weak C-H⋯π inter-actions are present in the crystal structure.

Diaqua-(5-carb-oxy-benzene-1,3-dicarboxyl-ato-κO,O)(6,6'-dimethyl-2,2'-bipyridine-κN,N')nickel(II) hepta-hydrate.

In the title compound, [Ni(C(9)H(4)O(6))(C(12)H(12)N(2))(H(2)O)(2)]·7H(2)O, the Ni(II) atom is six-coordinated by two O atoms from a chelating carboxyl-ate group of a 5-carb-oxy-benzene-1,3-dicarboxyl-ate ligand, two O atoms of two water mol-ecules and two N atoms from a 6,6'-dimethyl-2,2'-bipyridine ligand in a distorted octa-hedral geometry. The compound exhibits a three-dimensional supra-molecular structure composed of the complex mol-ecules and lattice water mol-ecules, which are linked together by inter-molecular O-H⋯O hydrogen bonds and partly overlapping π-π inter-actions between the pyridine and benzene rings [centroid-centroid distances = 3.922 (2) and 3.921 (2) Å]. One of the lattice water mol-ecules is disordered over two positions in an occupancy ratio of 0.521 (6):0.479 (6).

Synthesis, crystal structure and luminescent properties of one 3D Cd(II) coordination polymer [Cd(H3BPTC)2(bpy)]n (H4BPTC = 1,1'-biphenyl-2,2',6,6'-tetracarboxylic acid, bpy = 4,4'-bipyridine).

A new 3D metal-organic coordination polymer [Cd(H(3)BPTC)(2)(bpy)](n) (1) (H(4)BPTC = 1,1'-biphenyl-2,2',6,6'-tetracarboxylic acid, bpy =4,4'-bipyridine) has been synthesized and characterized by single X-ray diffraction and IR spectroscopy. The one-dimensional metal-organic chains of the title complex, namely [Cd(H(3)BPTC)(2)](n), are held together through hydrogen bonding and bridging "second" ligand 4,4'-bpy to give a three-dimensional metal-organic network. The thermal stability of complex 1 was studied by thermal gravimetric (TG) and differential thermal analysis (DTA). Compound 1 exhibits photoluminescence with an emission maximum at ca. 380 nm upon excitation at ca. 251 nm.

Surface-enhanced Raman scattering of patterned copper nanostructure electrolessly plated on arrayed nanoporous silicon pillars.

A new synthesized composite structure, a patterned copper/silicon nanoporous pillar array (Cu/Si-NPA) made by depositing Cu on Si-NPA using an immersion plating method, can be used as a surface-enhanced Raman scattering (SERS) substrate. Its surface component and morphology were analyzed by x-ray diffraction and field-emission scanning electron microscopy, respectively. It was found that the surface was Cu with two kinds of crystal structures: a continuous film composed of Cu nanocrystallites covering the Si-NPA, and a quasi-regular, interconnected network composed of loop-chains of Cu crystallites, with the size in the range of several tens of nanometer to 300 nm, surrounding the porous Si pillars. The composite structure is strongly SERS active using rhodamine 6G as probe molecules, which is mainly due to the patterned hierarchical Cu structure.