Reactivity of Hydride Bridges in High-Spin [3M-3(µ-H)] Clusters (M = FeII, CoII).

The designed [3M-3(µ-H)] clusters (M = Fe(II), Co(II)) Fe3H3L (1-H) and Co3H3L (2-H) [where L(3-) is a tris(ß-diketiminate) cyclophane] were synthesized by treating the corresponding M3Br3L complexes with KBEt3H. From single-crystal X-ray analysis, the hydride ligands are sterically protected by the cyclophane ligand, and these complexes selectively react with CO2 over other unsaturated substrates (e.g., CS2, Me3SiCCH, C2H2, and CH3CN). The reaction of 1-H or 2-H with CO2 at room temperature yielded Fe3(OCHO)(H)2L (1-CO2) or Co3(OCHO)(H)2L (2-CO2), respectively, which evidence the differential reactivity of the hydride ligands within these complexes. The analogous reactions at elevated temperatures revealed a distinct difference in the reactivity pattern for 2-H as compared to 1-H; Fe3(OCHO)3L (1-3CO2) was generated from 1-H, while 2-H afforded only 2-CO2.

Dinitrogen activation upon reduction of a triiron(II) complex.

Reaction of a trinuclear iron(II) complex, Fe3 Br3 L (1), with KC8 under N2 leads to dinitrogen activation products (2) from which Fe3 (NH)3 L (2-1; L is a cyclophane bridged by three ß-diketiminate arms) was characterized by X-ray crystallography. (1) H NMR spectra of the protonolysis product of 2 synthesized under (14) N2 and (15) N2 confirm atmospheric N2 reduction, and ammonia is detected by the indophenol assay (yield ∼30 %). IR and Mössbauer spectroscopy, and elemental analysis on 2 and 2-1 as well as the tri(amido)triiron(II) 3 and tri(methoxo)triiron 4 congeners support our assignment of the reduction product as containing protonated N-atom bridges.

Dichlorido[N,N-diethyl-N'-(2-pyridyl-methyl-ene)ethane-1,2-diamine]mercury(II).

The Hg atom in the title compound, [HgCl(2)(C(12)H(19)N(3))], adopts a distorted trigonal-bipyramidal geometry, being ligated by two Cl atoms and three N atoms of the N,N-diethyl-N'-(2-pyridylmethyl-ene)ethane-1,2-diamine ligand. The dihedral angle between the HgN(3) and HgCl(2 )least-squares planes is 88.6 (1)°. The Hg-N distances including the pyridine N and the ammonium N atom are about 0.20 Šlonger than the Hg-N distance including the imino N atom.

The Chevrel phase In(4.07)Mo(15)S(11.87)Se(7.13) with mixed chalcogenide occupancy.

The single-crystal of the title compound, indium pentadecamolybdenum nonadeca(sulfide/selenide), was obtained by solid state reaction with an S/Se mixture. It adopts the structure type of In(3)Mo(15)Se(19) and In(3.7)Mo(15)S(19), which are non-substituted Chevrel phases in the space group P6(3)/m. The Mo, one S/Se and two In sites have point symmetry m.. and two S/Se and one In atoms are in 3.. sites. This compound contains isolated Mo(6) and Mo(9) clusters. The shapes of clusters are octa-hedral and confacial biocta-hedral, respectively, face-capped by chalcogen atoms over each triangle face. The Mo-X bonds (X = S, Se) play an important role for the constitution of the framework. The Mo-X distances of 2.479 (2)-2.6687 (9) Šare within the ranges of average values of Mo-S and Mo-Se distances. The In atoms located on sites with m.. symmetry are partially occupied.

Bis(3-methyl-pyridinium) tetra-chlorido-cuprate(II).

The title compound, (C(6)H(8)N)(2)[CuCl(4)], is composed of two 3-methyl-pyridinium cation and one tetra-chloridocuprate(II) anion. The geometry around the copper(II) ion is that of a distorted tetra-hedron. In the crystal structure, the anions and cations are linked by three different N-H⋯Cl hydrogen bonds. In addition, the crystal structure exhibits aromatic π-π inter-actions between the pyridinium rings of two discrete units [centroid-centroid distance = 3.704 (2) Å].

anti-9,10-Di(1-naphth-yl)anthracene pyridine disolvate.

In the title compound, C(34)H(22)·2C(5)H(5)N, there is a crystallographic inversion center in the middle of the anthracene ring system. The dihedral angle between the mean planes of the anthracene and naphthalene ring systems is 83.96 (4)°. The crystal structure is stabilized by weak inter-molecular C-H⋯N and C-H⋯π inter-actions.

4-Hydroxy-phenyl 4-fluoro-benzoate.

In the title compound, C(13)H(9)FO(3), the dihedral angle between the two benzene rings is 59.86 (4)°. In the crystal, inter-molecular O-H⋯H hydrogen bonds lead to molecular chains propagating in [010].

[Benzyl(2-pyridylmeth-yl)amine]dichloridomercury(II).

The Hg atom in the title compound, [HgCl(2)(C(13)H(14)N(2))], adopts a distorted tetra-hedral geometry, being ligated by two N atoms of the benzyl(2-pyridylmeth-yl)amine (bpma) ligand and two Cl atoms. The dihedral angle between the least-squares planes through the chelate ring and Cl-Hg-Cl atoms is 85.4 (1)°. The phenyl ring on the bpma ligand is twisted out of the pyridine plane, forming a dihedral angle of 76.0 (3)°. Disorder in this ring is also noted with two coplanar conformations having equal site occupancies.

[Bis(2-pyridylmeth-yl)amine]dichloridomercury(II).

The Hg atom in the title complex, [HgCl(2)(C(12)H(13)N(3))], adopts a square-pyramidal geometry, being ligated by three N atoms of the tridentate bis-(2-pyridylmeth-yl)amine ligand and two Cl atoms, with one of the latter occupying the apical position. Disorder is noted in the amine portion of the ligand and this was modelled over two sites, with the major component having a site-occupancy factor of 0.794 (14).

N-(3,4-Difluoro-phen-yl)-2-(3,4-dimethoxy-phen-yl)acetamide.

In the title amide, C(16)H(15)F(2)NO(3), the dihedral angle between the benzene rings is 53.7 (1)°. Mol-ecules are linked in the crystal structure by an inter-molecular N-H⋯O hydrogen bond involving N-H and C=O functionalities of the amide group. A one-dimensional network is thus formed along the [001] direction. No significant inter-chain contacts are observed.

A three-coordinate Fe(ii) center within a [3Fe-(µ3-S)] cluster that provides an accessible coordination site.

A µ3-sulfide bridged triiron cluster(ii,ii,iii) supported by a cyclophane ligand undergoes metal-based reduction to yield an all-ferrous species. The latter complex incorporates a three-coordinate iron center that provides an accessible coordination site to a solvent molecule.

A [3Fe-3S](3+) cluster with exclusively µ-sulfide donors.

A [3Fe-3(µ-S)](3+) cluster is reported in which each ferric center has a distorted trigonal pyramidal geometry, with an S = 1/2 ground state for the cluster and unusually anisotropic hyperfine coupling constants as determined by variable temperature magnetometry and Mössbauer spectroscopy.