Tri- and Tetranuclear Nickel(II) Inverse Metallacrown Complexes Involving Oximato Oxygen Linkers: Role of the Guest Anion (Oxo versus Alkoxo) in Controlling the Size of the Ring Topology

3-Amino-1-propanol and N-methylaminoethanol: coordination to zinc(ii) vs. decomposition to ammonia

The coordination of amino alcohols 3-amino-1-propanol and N-methylaminoethanol to zinc(ii) and their decomposition to ammonia were investigated.

Ni(ii) complexes of the phosphine-oxime Ph2PC6H4-2-CH[double bond, length as m-dash]NOH

We report the solution and structural chemistry of nickel(ii) complexes of the phosphine-oxime Ph2PC6H4-2-CH[double bond, length as m-dash]NOH (PCH[double bond, length as m-dash]NOH). PCH[double bond, length as m-dash]NOH invariably binds in a bidentate manner as illustrated by cis-Ni(PCH[double bond, length as m-dash]NOH)2Cl2 and cis-[Ni(PCH[double bond, length as m-dash]NOH)2]2+ (as its BF4- salt). Treatment of PCH[double bond, length as m-dash]NOH with Ni(OAc)2(H2O)4 gave charge-neutral trans-[Ni(PCH[double bond, length as m-dash]NO)2]0. Treatment of trans-[Ni(PCH[double bond, length as m-dash]NO)2]0 with BF3 gave [Ni(PCH[double bond, length as m-dash]NO)2BF2]BF4. The cation features a planar NiP2N2 center wherein the pair of oximate groups are linked by the difluoroboryl center. The 1 : 1 complexes of the oxime and the oximate are illustrated by [Ni(PCH[double bond, length as m-dash]NOH)Cl2]2 and [Ni(C6F5)(PCH[double bond, length as m-dash]NO)]2, which feature five- and four-coordinate Ni(ii) centers, respectively. All complexes in this series hydrolyze to give the trinickel oxo-phosphine-oximate complex [Ni3(PCH[double bond, length as m-dash]NO)3O]+. One feature of the PCH[double bond, length as m-dash]NOH ligand is its wide bite angle combined with its protic OH center. These aspects are manifested in the structures of Ni(PCH[double bond, length as m-dash]NOH)2Cl2 and [Ni(PCH[double bond, length as m-dash]NOH)Cl2]2, which show intramolecular hydrogen bonding to terminal chloride ligands.

A novel 2-D Mn selenidostannate(iv) incorporating high-nuclear Mn clusters with spin canting behavior

A solvothermal reaction of SnCl₄·5H₂O, Mn and Se in ethanolamine (Hea) yielded a novel 2-D Mn selenidostannate(iv) [Mn₇(ea)₆(SnSe₄)₂]_n (1), which not only provides the first example of the incorporation of a hepta-nuclear Mn cluster [Mn₇(ea)₆]⁸⁺ into a selenidostannate(iv) framework, but also shows unusual spin canting behavior.

Counter-anion role in the formation of two supramolecular complexes: [Ag2(DPP)2](ClO4)2·CH3CN and [Ag2(DPP)2(NO3)2] {DPP is N-[(diphenylphosphanyl)methyl]pyridin-4-amine}

The title compounds, bis{μ-N-[(diphenylphosphanyl)methyl]pyridin-4-amine-κ(2)N(1):P}disilver bis(perchlorate) acetonitrile monosolvate, [Ag2(C18H17N2P)2](ClO4)2·CH3CN, (1), and bis{μ-N-[(diphenylphosphanyl)methyl]pyridin-4-amine-κ(2)N(1):P}bis[(nitrato-κ(2)O,O)silver], [Ag2(C18H17N2P)2(NO3)2], (2), each contain disilver macrocyclic [Ag2(C18H17N2P)2](2+) cations lying about inversion centres. The cations are constructed by two N-[(diphenylphosphanyl)methyl]pyridin-4-amine (DPP) ligands linking two Ag(+) cations in a head-to-tail fashion. In (1), the unique Ag(+) cation has a near-linear coordination geometry consisting of one pyridine N atom and one P atom from two different DPP ligands. Two ClO4(-) anions doubly bridge two metallomacrocycles through Ag···O and N-H···O weak interactions to form a chain extending in the c direction. The half-occupancy acetonitrile molecule lies with its methyl C atom on a twofold axis and makes a weak N···Ag contact. In (2), there are two independent [Ag(C18H17N2P)](+) cations. The nitrate anions weakly chelate to each Ag(+) cation, leading to each Ag(+) cation having a distorted tetrahedral coordination geometry consisting of one pyridine N atom and one P atom from two different DPP ligands, and two chelating nitrate O atoms. Each dinuclear [Ag2(C18H17N2P)2(NO3)2] molecule acts as a four-node to bridge four adjacent equivalent molecules through N-H···O interactions, forming a two-dimensional sheet parallel to the bc plane. Each sheet contains dinuclear molecules involving just Ag1 or Ag2 and these two types of sheet are stacked in an alternating fashion. The sheets containing Ag1 all lie near x = 1/2, 3/2, 5/2 etc, while those containing Ag2 all lie near x = 0, 1, 2 etc. Thus, the two independent sheets are arranged in an alternating sequence at x = 0, 1/2, 1, 3/2 etc. These two different supramolecular structures result from the different geometric conformations of the templating anions which direct the self-assembly of the cations and anions.