Metals in Metal Salts: A Copper Mirror Demonstration

A simple lecture demonstration is described to show the latent presence of metal atoms in a metal salt. Copper(II) formate tetrahydrate is heated in a round-bottom flask forming a high-quality copper mirror

Hydrogen-Bonding Networks in Heterocyclic Thioureas

The synthesis of heterocyclic thioureas from heterocyclic amines with phenyl- or methylisothiocyanate or CS2 is described. Seven new X-ray crystal structures are reported: In N-(3-pyridyl)-N′-phenylthiourea (Pna21, a = 10.1453(3), b = 17.6183(5), c = 6.4787(2), V = 1158.02(6), Z = 4) hydrogen-bonding results in formation of a 3D network consisting of helices, which form channels parallel to the c-axis. In N-(4-pyridyl)-N′-phenylthiourea (P21/c, a = 16.9314(3), b = 10.3554(2), c = 13.5152(3), β = 106.5080(10), V = 2271.96(8), Z = 4, two independent molecules) hydrogen-bonding results in N–H···S bridged dimers and N–H···Py chains, forming a 2D sheet network. In N-(2-pyrimidyl)-N′-phenylthiourea (P21/c, a = 5.45900(10), b = 13.8559(2), c = 14.3356(3), β = 94.9800(10), V = 1080.24(3), Z = 4) and N-(2-pyrimidyl)-N′-methylthiourea (P21/c, a = 8.8159(5), b = 11.2386(5), c = 7.7156(4), β = 95.629(2), V = 760.76(7), Z = 4) pairs of intra- and intermolecular N–H···N interactions produce dimers. Dimer formation through N–H···S occurs for N-(2-thiazolyl)-N′-methylthiourea (C2/c, a = 17.9308(3), b = 7.78260(10), c = 10.8686(2), β = 105.3740(10), V = 1462.42(4), Z = 8). Two symmetrically disubstituted thioureas were examined: N,N′-bis(2-pyridyl)thiourea (Fdd2, a = 15.1859(2), b = 30.1654(3), c = 9.44130(10), V = 4324.95(8), Z = 16) forms intra- and intermolecular N–H···Py hydrogen-bonds, forming a 1D zigzag chain and N,N′-bis(3-pyridyl)thiourea (P21/c, a = 13.2461(2), b = 6.26170(10), c = 12.3503(2), β = 96.0160(10), V = 1018.73(3), Z = 4) forms intermolecular N–H···Py hydrogen-bonds, resulting in 2D sheets

Copper(I) Thiocyanate Networks with Aliphatic Sulfide Ligands

A total of five new CuSCN-L compounds with alkyl sulfide ligands, L = methyl sulfide (Me2S), ethyl sulfide (Et2S), isopropyl sulfide (Pri2S) or tetrahydrothiophene (THT) have been prepared and characterized. X-ray crystal structures for four of the compounds were obtained. Two compounds were collected from solutions of CuSCN in Me2S: {[Cu(SCN)(Me2S)2]}n (1a) in the form of colorless blocks and (CuSCN)(Me2S) (1b) as a white powder. Neat mixtures of CuSCN in the other alkyl sulfide ligands yielded only one product each: {[Cu(SCN)(Et2S)]}n (2); {[Cu(SCN)(Pri2S)]}n (3); and {[Cu(SCN)(THT)2]}n (4). Crystals of 2 and 4 underwent destructive phase changes at lower temperatures. Two networks types were observed: 1:2 decorated 1-D chains (1a and 4) and 1:2 decorated 1-D ladders (2 and 3). Further network formation through bridging of the organic sulfide ligands was not observed

Copper(I) Chloride Carbonyl Polymers

Addition of bridging diamine ligands to methanolic solutions of CuCl under a CO purge produces the polymeric complexes [(CuCl)2(CO)2(biL)] (biL = diazabicyclo[2.2.2]octane (DABCO), piperazine (Pip), N,N‘-dimethylpiperazine (DMP)). X-ray crystal structures of the three complexes reveal rhombic OC−Cu(μ-Cl)2Cu−CO bridged by biL. Unsaturated bridging ligands fail to produce carbonyl-bearing products

Tetra­ethyl­ammonium tri-μ-phenolato-bis­[tricarbonyl­manganate(I)]

The title compound, (C8H20N)[Mn2(C6H5O)3(CO)6], was synthesized from [Mn(CO)3(CH3CN)3]BF4 and (C8H20N)(OC6H5). The binuclear anion exhibits a pseudo-threefold symmetry and contains two six-coordinate Mn atoms. Each metal atom is coordinated by three facially oriented CO ligands and three doubly-bridging phenolate ligands. The average O—Mn—O bond angle is 74.9 (7)° in the Mn2O3 metal–phenolate dimeric core, yielding a distorted octa­hedron for each metal

Azidotetrakis(trimethylphosphine)nickel(II) Tetrafluoroborate

The title complex, [Ni(N3)(C3H9P)4]BF4, is a nearly perfect trigonal bipyramid with the azide group at an apical position. The metal-azide bond angle, Nil-- NlmN2, of 138.6(5) ° is the largest observed for a terminal azide ligand

Tetraethylammonium tri-l-phenolatobis [Tricarbonylmanganate(I)]

The title compound, (C8H20N)[Mn2(C6H5O)3(CO)6], was synthesized from [Mn(CO)3(CH3CN)3]BF4 and (C8H20N)(OC6H5). The binuclear anion exhibits a pseudo-threefold symmetry and contains two six-coordinate Mn atoms. Each metal atom is coordinated by three facially oriented CO ligands and three doubly-bridging phenolate ligands. The average O-Mn-O bond angle is 74.9 (7)° in the Mn2O3 metal-phenolate dimeric core, yielding a distorted octa­hedron for each metal

Bis{μ-2,2′-[1,1′-(ethane-1,2-diyldinitrilo)diethyl­idyne]diphenolato}bis­[(benzoato-κO)manganese(III)] dihydrate

The title compound, [Mn2(C18H18N2O2)2(C7H5O2)2]·2H2O, was synthesized by the reaction between manganese(II) benzoate and the Schiff base generated in situ by the condensation of ethane-1,2-diamine and o-hydroxy­aceto­phen­one. The Jahn–Teller-distorted manganese(III) ions of the centrosymmetric dimer are connected through phen­oxy bridges. Hydrogen-bonding inter­actions between the uncoord­in­ated C=O of the benzoate and uncoordinated water mol­ecules link the dimers into a chain running parallel to the c axis

The Edge-Connectivity of Vertex-Transitive Hypergraphs

A graph or hypergraph is said to be vertex-transitive if its automorphism group acts transitively upon its vertices. A classic theorem of Mader asserts that every connected vertex-transitive graph is maximally edge-connected. We generalise this result to hypergraphs and show that every connected linear uniform vertex-transitive hypergraph is maximally edge-connected. We also show that if we relax either the linear or uniform conditions in this generalisation, then we can construct examples of vertex-transitive hypergraphs which are not maximally edge-connected.Comment: 8 page