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The present work focuses on the synthesis and characterization of poly(arylchalcone)’s (PCH I-IV) by reacting acetone with various dialdehydes for the first time at below ambient temperature followed by cyclization with phenylhydrazinehydrochloride to yield luminescent poly(arylpyrazoline)’s (PPY I-IV). The synthesized polymers were characterized by standard techniques such as, GPC, SEM, TGA, FT-IR, 1 H NMR, UV–Vis absorption and fluorescence spectroscopy, and electrochemical studies by cyclic voltammetry analyses. The Pyrazoline group hooked with different aryl donors such as benzene, thiophene, carbazole, triphenylamine, thus results a series of blue and green emitting materials. The obtained optical bandgap energy of the polymers (PPY I-IV) were 2.53, 3.41, 3.07, 3.10 eV respectively, suggest that all the polymers belongs to semiconducting category. The solvent effect of polymers was thoroughly studied and explained by Lippert-Mataga equation. The polymers I & IV display large degree of intra-molecular charge transfer in excited state evidenced from solvatochromic shift on the emission spectra. The obtained results demonstrate that they are promising materials for organic electronics applications. [ABSTRACT FROM AUTHOR]

A rare variety of self-assembled molecular triangle [Pd(bpy)(imidazolate)](NO), 1 is prepared by the combination of Pd(bpy)(NO) with imidazole, at 1:1 ratio, in acetonitrile-water. Deprotonation of imidazole happened during the course of the complexation reaction where upon the metallomacrocycle is formed. The bowl-shaped trinuclear architecture of 1 is crafted with three peripheral bpy units capable of π− π stacking interactions. While the solution state structure of 1can be best described as a trinuclear complex, in the solid-state well-fashioned intermolecular π− π and CH- π interactions are observed. Thus, in the solid-state further self-assembly of already self-assembled molecular triangle is witnessed. The triangular panels are arranged in a linear manner utilizing intermolecular π− π interactions where upon two out of three bpy units of each molecule participated in the chain formation. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: Chalcogen-stabilized dimolybdaboranes 3–5 (3: [(Cp∗Mo)2B4H5Se(Ph)], 4: [(Cp∗Mo)2B4H3Se2(SeCH2Ph)] and 5: [(Cp∗Mo)2B3H6(BSR)(μ-η1-SR)] (R=2,6-( t Bu)2-C6H2OH)) have been isolated from the mild pyrolysis of dichalcogenide ligands, RE-E‘R (R=Ph: E=S, E‘=Se; R=CH2Ph, [2,6-( t Bu)2-C6H2OH]: E=E‘=Se, S) and [(Cp∗Mo)2B4H8], 2, an intermediate generated from the reaction of [Cp∗MoCl4] (1) (Cp∗ =η5-C5Me5), with [LiBH4.thf]. The geometry of [(Cp∗Mo)2B4H5Se(Ph)] is similar to that of [(Cp∗Mo)2B5H9], in which one BH3 unit on the open face is replaced by a triple bridged selenium atom. All the compounds have been characterized in solution by 1H, 11B, 13C NMR and IR spectroscopy and elemental analysis. The structural types were unequivocally established by X-ray crystallographic analysis of compounds 3–5. [Copyright &y& Elsevier]

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]

In the crystal structure of the title compound, C31H25NO4, the five-membered heterocyclic ring is in an envelope conformation and the dihydropyrone ring is in a half-chair conformation. [ABSTRACT FROM AUTHOR]

Vanadaborane, [(CpV)2(B2H6)2] (Cp = η5-C5H5), 1 reacts with elemental sulfur to afford the hexasulfide cluster [(CpV)2S4(μ-η1-S2)], 2 in high yield. Compound 2 is a notable example of an organovanadium sulfide cluster in which the [V2S4] atoms define a bicapped tetrahedron framework, with one μ-η1-S2 ligand bridged the two (CpV) moieties. The sulfur atom in [V2S4] core in 2 is a four-skeletal-electron donor isoelectronic with the BH3 unit; therefore, the replacement of boron hydride in 1 by four sulfur atoms necessitates the formation of a bicapped tetrahedron [V2S4] framework. Furthermore, this is the only reported example of a bimetallic hexasulfide cluster containing vanadium. Pyrolysis of 1 with bis-chalcogenide ligands such as Ph2S2 and Bz2Se2 (Bz = PhCH2), results in the formation of substituted vanadahexaboranes [(CpV)2B4H12-xLx], 3-5 (3: L = SPh: x = 3; 4: L = SPh, x = 2; 5: L = SeBz: x = 1) in modest yield. All these new compounds have been characterized by mass, 1H, 11B, 13C NMR spectroscopy, and elemental analysis, and the structural types were unequivocally established by crystallographic analysis of compounds 2-5. [ABSTRACT FROM AUTHOR]

In a quest for effective synthetic precursors for the preparation of B-agostic complexes of ruthenium, we have shown that the reaction of [Cp*RuCl 2 ] 2 (Cp* = η5-C 5 Me 5 ) with [NaBt] or [NaBo] (Bt = dihydrobis(2-mercaptobenzthiazolyl)borate; Bo = dihydrobis(2-mercaptobenzoxazolyl)borate) led to the formation of B-agostic complexes [Cp*RuBH 2 L 2 ], 1a,b ( 1a : L = 2-mercaptobenzthiazol, 1b : L = 2-mercaptobenzoxazol) and [Cp*RuBH 3 L], 2a,b ( 2a : L = 2-mercaptobenzthiazol, 2b : L = 2-mercaptobenzoxazol) in good yields. In parallel to the formation of 1a,b and 2a,b , this method also allowed the formation of ruthenium hydrotrisborate complexes [Cp*RuBYL 3 ], 3a–c ( 3a : L = 2-mercaptobenzthiazol, Y = H; 3b : L = 2-mercaptobenzoxazol, Y = H; 3c : L = 2-mercaptobenzoxazol, Y = Cl). The key feature of complexes 3a–c is the coordination of one of the 2-mercaptobenzothiazole ligand that connects to the metal and the boron centre through a common sulfur atom. Upon heating, compounds 3a,b change into their corresponding S→N linkage isomers, in which the boron atom is bonded to three nitrogen atoms. The cyclic voltammetric studies on compounds 3a–c and 4a,b suggest that a deviation in coordination of the ligand change the oxidation potential of the metal centre. All the new compounds have been characterized in solution by 1 H, 11 B and 13 C NMR spectroscopy, mass spectrometry and the structural types of 3a–c and 4b were unequivocally established by crystallographic analysis. [ABSTRACT FROM AUTHOR]

Thermolysisof [(Cp*RuCO)2B2H6] (1; Cp* = η5-C5Me5) with [Ru3(CO)12] yielded the trimetallaborane[(Cp*RuCO)3(μ3-H)BH] (2)and a number of homometallic boride clusters: [Cp*RuCO{Ru(CO)3}4B] (3), [(Cp*Ru)2{Ru2(CO)8}BH] (4), and [(Cp*Ru)2{Ru4(CO)12}BH] (5). Compound 2is isoelectronic and isostructural with the triply bridgedborylene compounds [(μ3-BH)(Cp*RuCO)2(μ-CO){Fe(CO)3}] (6) and [(μ3-BH)(Cp*RuCO)2(μ-H)(μ-CO){Mn(CO)3}] (7), where the [μ3-BH] moiety occupies the apicalposition. To test if compound 2undergoes hydroborationreactions with alkynes, as observed with 6, we performedthe reaction of 2with the same set of alkynes underphotolytic conditions. However, neither 2nor 7undergoes hydroboration to yield a vinyl–borylene complex.On the other hand, thermolysis of 6with trimethylsilylethyleneyielded the novel diruthenacarborane [1,1,7,7,7-(CO)5-2,3-(Cp*)2-μ-2,3-(CO)-μ3-1,2,3-(CO)-5-(SiMe3)-pileo-1,7,2,3,4,5-Fe2Ru2C2BH] (8). The solid-state X-ray diffractionresults suggest that 8exhibits a pentagonal -bipyramidalgeometry with one additional CO capping one of its faces. Cluster 3is a boride cluster where boron is in the interstitial positionof a square-pyramidal geometry, whereas compound 4canbe described as a tetraruthenium boride in which the Ru4butterfly skeleton has an interstitial boron atom. Electronic structurecalculations of compound 2employing density functionaltheory (DFT) generate geometries in agreement with the structure determinations.The existence of a large HOMO–LUMO gap in 2isin agreement with its high stability. Bonding patterns in the structurehave been analyzed on the grounds of DFT calculations. Furthermore,the B3LYP-computed 11B and 1H chemical shiftsfor compound 2precisely follow the experimentally measuredvalues. All the compounds have been characterized by IR and 1H, 11B, and 13C NMR spectroscopy, and the geometriesof the structures were unambiguously established by crystallographicanalyses of 2–4and 8. [ABSTRACT FROM AUTHOR]

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]

In the title compound, C19H18Br2O2, the tetrahydropyran ring has a chair conformation with an equatorial disposition of all the methyl and p-bromophenyl groups. The structure is stabilized by intermolecular C—H...O, C—H...π and Br...Br interactions [Br...Br = 3.4756 (9) Å], forming a zigzag layer arrangement. [ABSTRACT FROM AUTHOR]