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Graphical abstract Two new bis- and mono-tridentate chelated iron complexes, [FeII(LH) 2 ](ClO 4) 2 ·C 2 H 5 OH (1) and [FeIII(LH)Cl 3 ]·0.5CH 2 Cl 2 (2), with facially capping N-tridentate ligand, 2-(5,7-dihydro-6H-dibenzo[c,e]azepin-6-yl)-N-(pyridin-2-ylmethyl)ethan-1-amine, incorporating biphenyl-append (LH), have been synthesized and characterized by X-ray crystal structure, spectroscopic (FTIR, UV–Vis and ESI-MS) and magnetic susceptibility measurements. Crystal structures of 1 and 2 reveal pseudo-octahedral geometry with two ligand (LH) molecules arranged in trans-facial manner and similar geometry with one facially capping ligand, LH and three Cl−, respectively. Their characterizations in solution by spectroscopic (FTIR, UV–Vis and ESI-MS) methods and a qualitative variable temperature (20–300 K) magnetic susceptibility (VSM) of solids complement solid state structures. Abstract Two new bis- and mono-tridentate chelated iron complexes, [FeII(LH) 2 ](ClO 4) 2 ·C 2 H 5 OH (1) and [FeIII(LH)Cl 3 ]·0.5CH 2 Cl 2 (2) , with facially capping N-tridentate ligand, 2-(5,7-dihydro-6H-dibenzo[c,e]azepin-6-yl)-N-(pyridin-2-ylmethyl)ethan-1-amine, incorporating biphenyl-append (LH), have been synthesized and characterized by X-ray crystal structure, spectroscopic (FTIR, UV–Vis and ESI-MS) and magnetic susceptibility measurements. Structure of 1 reveals pseudo-octahedral geometry around Fe(II) with two ligands (LH) arranged in trans-facial manner, in two crystallographic independent molecules, Mol. A and Mol. B, differing in biphenyl twist angles, ϕ = 43.7° and 45.1°. Complex 2 has similar geometry with Fe(III) having one facially capping ligand, LH and three chlorides (Cl−), also in two crystallographic independent molecules, Mol. A and Mol. B, differing by biphenyl twist angles, ϕ = 40.9° and −42.7°. The UV–Vis absorption spectrum of 2 in CH 3 CN suggests competitive coordination between the two weakly-coordinating tertiary amine nitrogen atoms having biphenyl-append, and the solvent, CH 3 CN. The qualitative magnetic susceptibility measurements for 1 and 2 at 296 K provide moments of 4.2 μ B and 2.7 μ B , respectively, suggesting nearly high-spin, Fe(II) (S = 2) and a rare intermediate-spin, Fe(III) (S = 3/2). [ABSTRACT FROM AUTHOR]

Novel bent-core materials containing a central core of 2, 5-disubstituted thiophene with chalcone as the side arm were synthesized and characterized to determine the structure–property relationship. The structural difference between two materials is the linking group in the thiophene and chalcone side arm. Chalcone is linked with thiophene by ester group in material I, while ester group is replaced with imine group in material II. The change in linking group exhibited a drastic difference in their physicochemical and intramolecular behaviors. Material I exhibits a hexagonal columnar mesophase at below room temperature, whereas material II exhibits a crystalline phase. Both liquid crystalline and crystalline properties were examined from polarized optical microscopy (POM), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) analyses. The highlight of this work is material I revealed a hexagonal columnar phase in the temperature ranges 22–38°C and undergoes photocrosslinking in UV light; contrarily, material II exhibits neither LC phase nor photocrosslinking property. [ABSTRACT FROM AUTHOR]

Trinuclear complexes of group 6, 8, and 9 transition metals with a (μ3-BH) ligand [(μ3-BH)(Cp*Rh)2(μ-CO)M′(CO)5], 3 and 4 ( 3: M′=Mo; 4: M′=W) and 5- 8, [(Cp*Ru)3(μ3-CO)2(μ3-BH)(μ3-E)(μ-H){M′(CO)3}] ( 5: M′=Cr, E=CO; 6: M′=Mo, E=CO; 7: M′=Mo, E=BH; 8: M′=W, E=CO), have been synthesized from the reaction between nido-[(Cp*M)2B3H7] ( nido- 1: M=Rh; nido- 2: M=RuH, Cp*=η5-C5Me5) and [M′(CO)5 ⋅thf] (M′=Mo and W). Compounds 3 and 4 are isoelectronic and isostructural with [(μ3-BH)(Cp*Co)2(μ-CO)M′(CO)5], (M′=Cr, Mo and W) and [(μ3-BH)(Cp*Co)2(μ-CO)(μ-H)2M′′H(CO)3], (M′′=Mn and Re). All compounds are composed of a bridging borylene ligand (B−H) that is effectively stabilized by a trinuclear framework. In contrast, the reaction of nido- 1 with [Cr(CO)5 ⋅thf] gave [(Cp*Rh)2Cr(CO)3(μ-CO)(μ3-BH)(B2H4)] ( 9). The geometry of 9 can be viewed as a condensed polyhedron composed of [Rh2Cr(μ3-BH)] and [Rh2CrB2], a tetrahedral and a square pyramidal geometry, respectively. The bonding of 9 can be considered by using the polyhedral fusion formalism of Mingos. All compounds have been characterized by using different spectroscopic studies and the molecular structures were determined by using single-crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Reaction of tetraethoxysilane (TEOS) with substituted catechols (I-X), 7,8-dihydroxyflavone (XI), 3,3′,4′-trihydroxyflavone (XII), 3′,4′,5,7-tetrahydroxyflavone (XIII), and 9-phenyl-2,3,7-trihydroxy-6-fluorone (XIV) in the presence of an amine (molar ratio 1:3:2) in acetonitrile affords the corresponding dianionic hexacoordinate silicon(IV) complexes 1-15 having a “SiO6” structural fragment. The dianionic silicates were isolated as di-n-propylammonium/triethylammonium/di-n-butylammonium salts and were characterized by elemental analysis and various spectroscopic data (IR, 1H, 13C, and 29Si NMR). The solid state structures of compounds [(n-C3H7)2NH2]2[{Cl4C6O2}3Si] (1) and [(n-C3H7)2NH2]2[{Br4C6O2}3Si] (2) were determined by single crystal X-ray diffraction. Both 1 and 2 crystallize in the monoclinic space group C2/c and reveal (i) bidentate mode of ligation, (ii) octahedral coordination around silicon, and (iii) hydrogen bonding features. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. GRAPHICAL ABSTRACT [ABSTRACT FROM AUTHOR]

Abstract: A different approach developed for the preparation of palladium(II) based complexes [(Pd(bpy)) x (L) y ](NO3)2 x is modelled by using 4-phenylpyridine as ligand (L = 1). Various solvent systems are inspected to optimize the reaction condition for the preparation of the model complex [Pd(bpy)(4-phenylpyridine)2](NO3)2. The model complex is obtained quantitatively as a single product from a 1:1:2 mixture of Pd(NO3)2, 2,2′-bipyridine and 4-phenylpyridine when stirred at room temperature in CH3CN:H2O (1:1). The same reaction is performed in CD3CN:D2O (1:1) to monitor the progress of the reaction by recording 1H NMR. The kinetic products that formed initially got self-healed to give the desired product with in 6h. However, in DMSO-d 6 spontaneous arrangement leading to the targeted complex was observed and no kinetic product could be detected. When a similar reaction is performed with ethylenediamine instead of 2,2′-bipyridine a mixture of compounds are observed. Theoretical calculation throws some light on the principle behind the success of this method for the bpy based systems. The assembly, [Pd(bpy)(4-phenylpyridine)2](NO3)2 has been characterised by NMR, ESI-MS and single-crystal X-ray diffraction methods. [Copyright &y& Elsevier]

Abstract: The reaction of an intermediate, generated from [Cp#MoCl4] [Cp# = Cp or Cp∗; Cp = (η 5-C5H5), Cp∗ = (η 5-C5Me5)] and LiBH4.thf, with different chalcogen ligands yielded trimolybdaborane clusters 1–3, [(Cp#Mo)3(μ-H)B8H6X2], (1: Cp# = Cp, X = H; 2: Cp# = Cp∗, X = H; 3: Cp# = Cp∗, X = Cl). Compounds 1–3 constitute an example of an unsaturated (n-4) sep cluster having very close structural similarities. These clusters represent 11-vertex boron-rich metallaboranes containing 66 cluster valence electrons (cve). All the compounds were fully characterized by various spectroscopic techniques, elemental analysis and the solid state structures were unequivocally established by X-ray diffraction analysis of 1–3. [Copyright &y& Elsevier]