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The preparation of the [NBu(sub 4)][Pt(C(sub 6)F(sub 5))(sub 3)L] complexes containing triazene (L), formamidine and 2-aminopyridine was carried out. In formamidine the Pt-H bond interaction is stable enough to be detected in the solution whereas in 2-aminopyridine the Pt-H bond can be observed in crystal but not in solution.

The involvement of silver in two‐electron AgI/AgIII processes is currently emerging. However, the range of stability of the required and uncommon AgIII species is virtually unknown. Here, the stability of AgIII towards the whole set of halide ligands in the organosilver(III) complex frame [(CF3)3AgX]− (X=F, Cl, Br, I, At) is theoretically analyzed. The results obtained depend on a single factor: the nature of X. Even the softest and least electronegative halides (I and At) are found to form reasonably stable AgIII−X bonds. Our estimates were confirmed by experiment. The whole series of nonradiative halide complexes [PPh4][(CF3)3AgX] (X=F, Cl, Br, I) has been experimentally prepared and all its constituents have been isolated in pure form. The pseudohalides [PPh4][(CF3)3AgCN] and [PPh4][(CF3)3Ag(N3)] have also been isolated, the latter being the first silver(III) azido complex. Except for the iodo compound, all the crystal and molecular structures have been established by single‐crystal X‐ray diffraction methods. The decomposition paths of the [(CF3)3AgX]− entities at the unimolecular level have been examined in the gas phase by multistage mass spectrometry (MSn). The experimental detection of the two series of mixed complexes [CF3AgX]− and [FAgX]− arising from the corresponding parent species [(CF3)3AgX]− demonstrate that the Ag−X bond is particularly robust. Our experimental observations are rationalized with the aid of theoretical methods. Smooth variation with the electronegativity of X is also observed in the thermolyses of bulk samples. The thermal stability in the solid state gradually decreases from X=F (145 °C, dec.) to X=I (78 °C, dec.) The experimentally established compatibility of AgIII with the heaviest halides is of particular relevance to silver‐mediated or silver‐catalyzed processes. [ABSTRACT FROM AUTHOR]

The reactions of [Re(N‐N)(CO)3(PMe3)]OTf (N‐N=2,2′‐bipyridine, bipy; 1,10‐phenanthroline, phen) compounds with tBuLi and with LiHBEt3 have been explored. Addition to the N‐N chelate took place with different site‐selectivity depending on both chelate and nucleophile. Thus, with tBuLi, an unprecedented addition to C5 of bipy, a regiochemistry not accessible for free bipy, was obtained, whereas coordinated phen underwent tBuLi addition to C2 and C4. Remarkably, when LiHBEt3 reacted with [Re(bipy)(CO)3(PMe3)]OTf, hydride addition to the 4 and 6 positions of bipy triggered an intermolecular cyclodimerization of two dearomatized pyridyl rings. In contrast, hydride addition to the phen analog resulted in partial reduction of one pyridine ring. The resulting neutral ReI products showed a varied reactivity with HOTf and with MeOTf to yield cationic complexes. These strategies rendered access to ReI complexes containing bipy‐ and phen‐derived chelates with several C(sp3) centers. [ABSTRACT FROM AUTHOR]

The new complex [Dy(PDOA)(NO3)(H2O)2]n·nH2O (1) (H2PDOA is o-phenylenedioxydiacetic acid) was isolated from the reaction of dysprosium(III) nitrate and H2PDOA in a 1 : 1 molar ratio. Its crystal structure is formed of neutral zig-zag chains in which the nona-coordinated Dy(III) atoms (O9 donor set) are linked by PDOA ligands with a chelating-bridging coordination mode. DC and AC magnetic studies revealed that 1 behaves as a field-induced SMM with three relaxation channels. The derived values, considering the Orbach relaxation process, of the barrier to spin reversal and the extrapolated relaxation time are U/kB = 59.5 K and τ0 = 6.3 × 10−10 s, respectively. Ab initio calculations support the experimental results. [ABSTRACT FROM AUTHOR]

This educational review postulates the importance of maintaining an adequate level of crystallographic education among structure-dependent scientists whose interests are not primarily in crystallography, at a time when automation and validation have made it possible to obtain high-quality structure analyses in many cases with a minimum of crystallographic background. The topics addressed are intended to form a second round of crystallographic education for a novice user whose first round involved hands-on experience with structure solution and an introduction to elementary concepts. The specific topics, chosen for their relevance as basic knowledge and their lack of emphasis in many formal treatments, are (1) crystallographic reference frames and the utility of the reciprocal cell in geometrical calculations; (2) the relationship between the two concepts that constitute our model of the crystal, namely the unit cell and the lattice; (3) the manner in which an atom is represented in concept and in practice; (4) the importance of interleaved symmetry elements required by the presence of additional symmetry on a lattice; (5) the harnessing of the natural properties of the crystalline state for the potential manipulation of properties of synthetic crystals; and (6) useful terminology for navigating a crystal structure. [ABSTRACT FROM AUTHOR]

A heteromorphous, reversible single-crystal-to-single transformation involving cross-linking of a 1-dimensional (1-D) polymer of cobalt cubanes has formed a 2-D net. The results have shown that thermally provoked SC-SC transformations have involved significant chemical rearrangement.

The phosphorus ylide ligand [Ph3P=C(CO2Me)C(=NPh)CO2Me] is prepared and fully characterized by spectroscopic, crystallographic, and density functional theory (DFT) methods (B3LYP level). The increasing strength of the Pd-C, Pd-O and Pd-N bonds along with other subtle effects are responsible for the relative stabilities of the different bonding modes.

The formation, structure and spectroscopic and photophysical behavior of (NBu4)3[Tl{PtR4}2], (NBu4)(sub infinity)-[Tl{PtR4}](sub infinity) and (NBu4)(sub infinity)[Tl{PtR4}](sub infinity).{(NBu4)(PF6)}(sub infinity) are described and the solid state and solution photophysical properties are examined. Results show that their the emissions strongly depend on the solvent, concentration and excitation wavelength.

The title hydrated mol­ecular salt (systematic name: tetra-n-butyl­ammonium 2,6-dioxo-1,2,3,6-tetra­hydro­pyrimidine-4-carboxyl­ate monohydrate), C16H36N+·C5H3N2O4−·H2O, crystallizes with N—H∙∙∙O and O—H∙∙∙O hydrogen-bonded double-stranded anti­parallel ribbons consisting of the hydro­philic orotate monoanions and water mol­ecules, separated by the bulky hydro­phobic cations. The hydro­phobic and hydro­philic regions of the structure are joined by weaker non-classical C—HO hydrogen bonds. An accurate structure analysis conducted at T = 100 K is compared to a lower-resolution less accurate determination using data measured at T = 295 K. The results of both analyses are evaluated using a knowledge-based approach, and it is found that the less accurate room-temperature structure analysis provides geometric data that are similar to those derived from the accurate low-temperature analysis, with both sets of results consistent with previously analyzed structures. A minor disorder of one methyl group in the cation at low temperature was found to be slightly more complex at room temperature; while still involving a minor fraction of the structure, the disorder at room temperature was found to require a non-routine treatment, which is described in detail. [ABSTRACT FROM AUTHOR]

Three new isomorphous complexes [Ni(o-van-en)LnCl3(H2O)] [H2(o-van-en) = N,N′-ethylene-bis(3-methoxysalicylaldiminate; Ln = Ce (1), Gd (2), Dy (3)] were prepared by a stepwise reaction using mild conditions and were structurally characterised as dinuclear molecules in which Ni and Ln are coordinated by the compartmental Schiff base ligand (o-van-en)= and doubly bridged by O atoms. While the nickel(II) centre is diamagnetic within the N2O2 square-planar coordination of the Schiff base ligand, the lanthanide atoms are octa-coordinated to give an {LnCl3O5} chromophore with a fac-arrangement of the chlorido ligands. AC magnetic measurements revealed that all three complexes, including the nominally isotropic Gd(III) system, show field induced slow magnetic relaxation with two or three relaxation channels: at T = 1.9 K the low-frequency relaxation time is τLF(1) = 0.060 s at BDC = 0.5 T, τLF(2) = 0.37 s at BDC = 0.3 T, and τLF(3) = 1.29 s at BDC = 0.15 T. [ABSTRACT FROM AUTHOR]

Reactions of Co(OH)2 with the Schiff base bis(2‐hydroxy‐3‐methoxybenzylidene)ethylenediamine, denoted H2(o‐van‐en), under different conditions yielded the previously reported complex aqua[bis(3‐methoxy‐2‐oxidobenzylidene)ethylenediamine]cobalt(II), [Co(C18H18N2O4)(H2O)], 1, under anaerobic conditions and two polymorphs of [μ‐bis(3‐methoxy‐2‐oxidobenzylidene)ethylenediamine]bis{[bis(3‐methoxy‐2‐oxidobenzylidene)ethylenediamine]cobalt(III)} acetonitrile tetrasolvate, [Co2(C18H18N2O4)3]·4CH3CN, i.e. monoclinic 2 and triclinic 3, in the presence of air. Both novel polymorphs were chemically and spectroscopically characterized. Their crystal structures are built up of centrosymmetric dinuclear [Co2(o‐van‐en)3] complex molecules, in which each CoIII atom is coordinated by one tetradentate dianionic o‐van‐en ligand in an uncommon bent fashion. The pseudo‐octahedral coordination of the CoIII atom is completed by one phenolate O and one amidic N atom of the same arm of the bridging o‐van‐en ligand. In addition, the asymmetric units of both polymorphs contain two acetonitrile solvent molecules. The polymorphs differ in the packing orders of the dinuclear [Co2(o‐van‐en)3] complex molecules, i.e. alternating ABABAB in 2 and AAA in 3. In addition, differences in the conformations, the positions of the acetonitrile solvent molecules and the pattern of intermolecular interactions were observed. Hirshfeld surface analysis permits a qualitative inspection of the differences in the intermolecular space in the two polymorphs. A knowledge‐based study employing Full Interaction Maps was used to elucidate possible reasons for the polymorphism. Reactions of Co(OH)2 with the Schiff base bis(2‐hydroxy‐3‐methoxybenzylidene)ethylenediamine (o‐van‐en) yielded previously reported [CoII(o‐van‐en)(H2O)] under anaerobic conditions and two novel polymorphs of [CoIII2(o‐van‐en)3]·4CH3CN in the presence of air. Structural data were used in a knowledge‐based approach to elucidate the origin of the polymorphism. [ABSTRACT FROM AUTHOR]

The unusual transformation of N-arylbenzohydroxamic acids mediated by an osmium complex, [Os(bpy)(sub 2)Br(sub 2), affording a family of cyclometalates of osmium)III) where the transformed hydoxamic acids are coordinated as doubly deprotonated benzanilides are reported. The findings show that benzanilides are capable of functioning as bidentate, C,N-donor ligands.

The dinuclear heterometallic complex [(CN)3 Pt(Mu-CN)Cu(NH3)4] is obtained in the solid state, and its structure is determined by the X-ray diffraction techniques at two temperature. The preparation and solid-state characterization of the dinuclear heterometallic complex compound with a hydrogen bond donor, is reported.