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We have successfully synthesized the dichloro-bis[(Z)-1-styryl-benzimidazole]-zinc(II) complex, which was fully characterized by IR, elemental analysis, and mass and NMR spectroscopy. The solid-state structure definitively shows that two benzimidazole moieties are coordinated to the zinc atom, which adopts a tetrahedral geometry. [ABSTRACT FROM AUTHOR]

Dichloro-bis(1-cinnamyl-benzimidazole)-cobalt(II) was prepared in one step using a cobalt precursor CoCl2 and corresponding substituted benzimidazole. The complex was fully characterized using IR, elemental analysis, and mass- and NMR spectroscopy. In the solid state, the cobalt atom displays a typical tetrahedral geometry and is coordinated to two chlorine atoms and two benzimidazole moieties. [ABSTRACT FROM AUTHOR]

We report the synthesis and structural characterization of three crystalline borylated ortho-silylaryl trifluoromethanesulfonates: 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-(trimethylsilyl)phenyl trifluoromethanesulfonate, C16H24BF3O5SSi (1a), 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-(trimethylsilyl)phenyl trifluoromethanesulfonate, C16H24BF3O5SSi (1b), and 2-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-6-(trimethylsilyl)phenyl trifluoromethanesulfonate, C17H26BF3O5SSi (2), which are versatile aryne precursors. For all three compounds, the heteroatom substituents are almost coplanar with the central aromatic moiety. C—heteroatom bonding metrics are unexceptional and fall withing the typical range of C—B, C—Si, and C—O single bonds. Despite numerous electronegative sites, only weak intermolecular interactions are observed in the solid state.

We report the synthesis and structural characterization of three crystalline borylated ortho-silylaryl trifluoromethanesulfonates: 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-(trimethylsilyl)phenyl trifluoromethanesulfonate, C16H24BF3O5SSi (1a), 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-(trimethylsilyl) phenyl trifluoromethanesulfonate, C16H24BF3O5SSi (1b), and 2-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-6-(trimethylsilyl)phenyl trifluoromethanesulfonate, C17H26BF3O5SSi (2), which are versatile aryne precursors. For all three compounds, the heteroatom substituents are almost coplanar with the central aromatic moiety. C--heteroatom bonding metrics are unexceptional and fall withing the typical range of C--B, C--Si, and C--O single bonds. Despite numerous electronegative sites, only weak intermolecular interactions are observed in the solid state. [ABSTRACT FROM AUTHOR]

The octahydridotriborate anion plays a crucial role in the field of polyhedral boron chemistry, facilitating the synthesis of higher boranes and the preparation of diverse transition metal complexes. Among the stable forms of this anion, CsB3H8 (or (n-C4H9)4N)[B3H8] have been identified. These salts serve as valuable precursors for the synthesis of metallaboranes, wherein the triborate anion acts as a ligand coordinating to the metal center. In this study, we have successfully synthesized a novel rhodatetraborane dihydride, [Rh(η2-B3H8)(H)2(PPh3)2] (1), which represents a Rh(III) complex featuring a bidentate chelate ligand fasormed by B3H8−. Extensive characterization of this rhodatetraborane complex has been performed using NMR spectroscopy in solution and X-ray diffraction analysis in the solid state. Notably, the complex exhibits intriguing fluxional behavior, which has been investigated using NMR techniques. Moreover, we have explored the reactivity of complex 1 towards pyridine (py) and dimethylphenylphosphine (PMe2Ph). Our findings highlight the labile nature of this four-vertex rhodatetraborane as it undergoes disassembly upon attack from the corresponding Lewis base, resulting in the formation of borane adducts, LBH3, where L = py, PMe2Ph. Furthermore, in these reactions, we report the characterization of new cationic hydride complexes, such as [Rh(H)2(PPh3)2 (py)]+ (2) and [Rh(H)2(PMe2Ph)4]+. Notably, the latter complex has been characterized as the octahydridotriborate salt [Rh(H)2(PMe2Ph)4][B3H8] (3), which extends the scope of rhodatetraborane derivatives. [ABSTRACT FROM AUTHOR]

Cellulose model compounds that mimic the building blocks of modified cellulose and cellulose derivatives are widely used in cellulose research to infer the properties of the polymer from the monomer. Based on the well-established model compound methyl 4-O-methyl β-d-glucopyranoside, in which the methyl groups represent the truncated side chains of the cellulose, the corresponding O-methyl-substituted derivatives with all eight different substitution patterns (mono-, di- and trisubstituted at O-2, O-3, O-6) were synthesized. Crystallization of the products in sufficient quality for solid-state structure determination by single-crystal X-ray diffraction succeeded in all cases, and the results are reported. Two of the compounds showed more than one independent molecule per unit cell. Solid-state 13C NMR showed a significant down-field shift (5–10 ppm) of the OMe-substituted carbons relative to the OH-substituted counterparts and generally confirmed the important influence of solid-state packing on the chemical shifts as seen by comparison to the solution NMR data. [ABSTRACT FROM AUTHOR]

A series of new thiazolo[3,2-a]pyrimidines different by aryl substituents in 2 and 5 positions are synthesized and characterized in solution as well as in the crystalline phase using 1H and 13C NMR-, IR-spectroscopies, mass-spectrometry methods, and single crystal X-ray diffraction (SCXRD). The SCXRD study revealed the role of intermolecular H-bonding in the formation of supramolecular architectures (racemic monomers, centrosymmetric racematic dimers, or homochiral 1D chains) of obtained thiazolo[3,2-a]pyrimidines derivatives depending on solvents (aprotic DMSO or protic EtOH) used upon the crystallization process. Moreover, the in vitro study of cytotoxicity toward different tumor cells showed their high or moderate efficiency with moderate cytotoxicity against normal liver cells which allows to consider the obtained thiazolo[3,2-a]pyrimidine derivatives as promising candidates for application as antitumor agents. [ABSTRACT FROM AUTHOR]

Crystals of penta(carboxymethyl)diethylenetriamine have been structurally characterized through single‐crystal X‐ray diffraction analysis. X‐ray diffraction analysis reveals that various non‐covalent interactions combine to determine the crystal packing and final solid‐state supramolecular assembling behavior. The title compound exhibited various 2D supramolecular networks generated through O−H⋅⋅⋅O and C−H⋅⋅⋅O interactions. The C−H⋅⋅⋅O interactions are pivotal in building a two‐dimensional framework, whose formation is readily analyzed with zero‐dimensional centrosymmetric dimeric rings as building blocks within the structure. All the intermolecular interactions are quantified through Hirshfeld surface analysis and fingerprint plots. Energy frameworks are constructed to analyze the dominant interaction energy involved in molecular packing strength. Bader's quantum theory of "atoms‐in‐molecules" (QTAIM) has been used to analyze and characterize non‐covalent interactions. The QTAIM analysis validates the existence of hydrogen bonding contacts, and the topological properties of bond critical points (BCPs), such as the electron density ρ(r) and its Laplacian ∇2ρ(r), are presented to correlate with the interaction energy. The topological analysis revealed that all of the interactions are closed‐shell interactions. Finally, the "Non‐covalent Interaction" (NCI) plot index illustrates the solid‐state supramolecular networks. [ABSTRACT FROM AUTHOR]

The trigonal planar unit possesses significant hyperpolarizability and polarizability anisotropy, which makes it useful for optimizing nonlinear optical (NLO) materials, however, chalcogenide with this unit has seldom been reported. In this work, a novel approach is introduced by integrating the unprecedented trigonal planar MS 3 (M = Cd/In, Hg/In) motifs into the nearly optically isotropic tetrahedral units, resulting in two novel chalcogenides CsM 2 In 2 S 6 (M = Cd/In, 1; Hg/In, 2). Notably, structures 1 and 2 feature nearly planar triangular units at the center, encircled by three trimers, further interconnecting each other to create 3D frameworks. Importantly, phases 1 and 2 display phase-matching (PM) capabilities, primarily attributed to incorporating trigonal planar MS 3 units that additionally enhance polarizability anisotropy. Furthermore, compounds 1 and 2 demonstrate moderate second-harmonic generation (SHG) signals (0.70 and 0.84 × AgGaS2@1.7 µm). This study pioneers an efficient strategy for the design of infrared NLO crystals with PM capabilities., (© 2024 Wiley‐VCH GmbH.)

Ditetrelenes R2E=ER2 (E=Si, Ge, Sn, Pb) substituted by multiple N/P/O/S‐donor groups are extremely rare due to their propensity to disaggregate into their tetrylene monomers R2E. We report the synthesis of the first fully phosphanyl‐substituted digermene {(Mes)2P}2Ge=Ge{P(Mes)2}2 (3, Mes=2,4,6‐Me3C6H2), which adopts a highly unusual structure in the solid state, that is both strongly trans‐bent and highly twisted. Variable‐temperature 31P{1H} NMR spectroscopy suggests that 3 persists in solution, but is subject to a dynamic equilibrium between two conformations, which have different geometries about the Ge=Ge bond (twisted/non‐twisted) due to a difference in the nature of their π‐stacking interactions. Compound 3 undergoes unprecedented, spontaneous decomposition in solution to give a unique GeI cluster {(Mes)2P}4Ge4⋅5 CyMe (7). [ABSTRACT FROM AUTHOR]

Stabilization of residual point defects at the finishing stages of noise diodes can be ensured by the selection of appropriate ignition modes and the environment of its conduct. The method and technology of reducing the concentration of point defects in the structure of p-n-transition, taking into account the content of impurities of secondary metals, oxygen and nitrogen is proposed. It has been established that the burning of readymade structures and diodes of noise generators in nitrogen environments at temperatures of 450…600 °С for (80 ± 3) min leads to an increase in spectral noise density and a significant (twice) reduction of its unevenness. The most important result of this burn is a reduction in the spread of the average values of the noise parameters studied: by 61.2 % in effective noise voltage; spectral density by 34.2 %; at the boundary frequency of the signal by 34.9 %; in non-linear density by 25.9 %. This improves the quality of random numerical sequences in information protection software systems.

Adding to the versatile class of ionic liquids, we report the detailed structure and property analysis of a new class of asymmetrically substituted imidazolium salts, offering interesting thermal characteristics, such as liquid crystalline behavior, polymorphism or glass transitions. A scalable general synthetic procedure for N‐polyaryl‐N'‐alkyl‐functionalized imidazolium salts with para‐substituted linker (L) moieties at the aryl chain, namely [LPhmImHR]+ (L=Br, CN, SMe, CO2Et, OH; m=2, 3; R=C12, PEGn; n=2, 3, 4), was developed. These imidazolium salts were studied by single‐crystal X‐ray diffraction (SC‐XRD), NMR spectroscopy and thermochemical methods (DSC, TGA). Furthermore, these imidazolium salts were used as N‐heterocyclic carbene (NHC) ligand precursors for mononuclear, first‐row transition metal complexes (MnII, FeII, CoII, NiII, ZnII, CuI, AgI, AuI) and for the dinuclear Ti‐supported Fe‐NHC complex [(OPy)2Ti(OPh2ImC12)2(FeI2)] (OPy=pyridin‐2‐ylmethanolate). The complexes were studied concerning their structural and magnetic behavior via multi‐nuclear NMR spectroscopy, SC‐XRD analyses, variable temperature and field‐dependent (VT‐VF) SQUID magnetization methods, X‐band EPR spectroscopy and, where appropriate, zero‐field 57Fe Mössbauer spectroscopy. [ABSTRACT FROM AUTHOR]

FcC(O)CH=C(OH)R (1, R=Me; 2, R=Fc; Fc=Fe(η5‐C5H4)(η5‐C5H5)) reacts with 1‐H2N‐4‐R'‐C6H4 (3 a, R'=Me; 3 b, R'=OMe; 3 c, R'=C≡N; 3 d, R'=F) producing β‐ketoamines FcC(O)CH=C(NH(C6H4‐4‐R'))R (4 a–d, R=Me; 5 a–d, R=Fc). Electrochemistry shows that 4 a–d possess one (4 a: E°′=90 mV; 4 b: E°′=80 mV; 4 c: E°′=145 mV; 4 d: E°′=95 mV) and 5a–d two (5 a: E°′1,2=90, 305 mV; 5 b: E°′1,2=85, 305 mV; 5 c: E°′1,2=155, 360 mV; 5 d: E°′1,2=105, 325 mV) reversible redox processes. In 5 a–d electrostatic interactions occur among Fc/[Fc]+ as oxidation progresses, as evidenced by UV/vis‐NIR spectroscopy. Compounds 4 a,d and 5 b,c display an irreversible N‐oxidation at 1100–1450 mV, while 4 b owns a reversible event at 910 mV. A linear relationship between the σ Hammett constants and the E°′1 values exists. [ABSTRACT FROM AUTHOR]

Million tons of cellulosic paper have been used for insulating coils in oil-filled electrical power transformers, thereby assuring the electricity supply for our societies. The high working temperatures in transformers constantly degrade paper insulators throughout their service life of up to 40 years. We approached the structural changes in oil-immersed cellulosic paper samples upon thermal stress in a study that compared unbleached softwood Kraft paper used as insulator paper with pure cotton cellulose paper. The model experiments used a thermal treatment in transformer oil at 170 °C for up to 14 days. The samples were characterized by means of 13C CP/MAS NMR spectroscopy, mainly based on deconvolution of the C4 resonance. An automated, fast, and reproducible C4 resonance deconvolution employing the "Peak Analyzer" tool of OriginPro 2020 (OriginLab Corporation, USA) was developed and used to exploit 13C CP/MAS NMR spectroscopy for the characterization of thermally stressed paper samples. Our results show that thermally induced structural changes depend heavily on the composition of paper, that hornification and coalescence of fibrils take place, and that the allomorph composition of cellulose crystallites is altered under the given conditions. [ABSTRACT FROM AUTHOR]

• A click reaction used to synthesize ferrocene-based 1,4-disubstituted-1,2,3-triazole. • The physical properties determined for the titled compounds. • Electrochemical properties investigated for dendrimer-like ferrocenyl derivatives. • Quantum-chemical calculations for structural and electronic information performed. The synthesis and characterization of the two new ferrocenyl-based 1,4-disubstituted-1,2,3-triazole compounds 4 (1,1′-bis[[(4-ferrocenyl-1,2,3-triazol-1-yl-methyl)dimethylsilyl]ethyl]ferrocene) and 8 (1,1′,2,2'-tetrakis[[(4-ferrocenyl-1,2,3-triazol-1-yl-methyl)dimethylsilyl]ethyl]ferrocene) is reported. The molecular structure of 4 in the solid state was determined by single crystal X-ray structure analysis and a detailed structural analysis of the noncovalent interactions and their evaluation using Hirshfeld surface analysis is reported, evidencing the importance of C−H∙∙∙N, π∙∙∙π, C–H∙∙∙π, C–H∙∙∙C interactions and C–H∙∙∙H–C contacts. The electrochemical characteristics of 4 and 8 , were investigated using cyclic voltammetry (CV) and square wave voltammetry (SWV). Finally, quantum-chemical calculations were performed to gain further structural and electronic information. A click reaction performed to synthesize ferrocene-based 1,4-disubstituted-1,2,3-triazole. Their characterization, physical and electrochemical properties were investigated. In Addition, Quantum-chemical calculations for further structural and electronic information performed. [Display omitted] [ABSTRACT FROM AUTHOR]

The precursor (5,10,15,20)-tetratolylporphyrin (H2TTP) (1) and Zn(II) complex (5,10,15,20)-tetratolylporphyrinato)zinc(II) [Zn(TTP)] (2) have been synthesized and utilized to afford a novel complex (3) bearing pyrazine as fifth coordination site on axial position, i.e. (pyrazine)(5,10,15,20-tetratolylporphyrinato)zinc(II) hemi-pyrazine hemidichloromethane solvate [Zn(TTP) (pyz)]0.0.5(pyz.CH2Cl2). Photophysical, electrochemical and X-ray diffraction were investigated. The single-crystal X-ray analysis indicated that in complex (3) (i) Zn(II) ion is penta coordinated, (ii) slight displacement of Zn atom by −0.28 Å towards the axial ligand (pyrazine) and (iii) the crystal lattice is made up of two dimensional layers stabilised by C−H…Cg intra- and intermolecular interactions (Cg is the centroid of pyrrole ring). Optical absorption studies revealed a redshifted of the Soret (B) and Q bands of the Zn-porphyrins complexes. Contrarily, a hypsochromic shift of Q bands in emission spectra of the complexes is noted as compared to the H2TPP. Lifetime of the electrons in (1–3) were determined and compared. Overall, this study would assist in understanding the impact of incorporation of pyrazine at the axial position on optical and electronic properties. Cyclic voltammetry (CV) was applied for the study of the electrochemical behavior of both (2) and (3) complexes in 0.2 M Tetra-n-butyl ammonium perchlorate (TBAP) solution in CH2Cl2. The results of electrochemical confirmed the potentials redox peaks shift more negative ca 60 mV to that is caused by the coordination of pyrazine ligand.

Solution combustion synthesis followed by annealing in air led to the MPTB‐related phosphates (Rh1/6W5/6O3)8(PO2)4, (Ir1/6W5/6O3)8(PO2)4 (a=5.258(2) Å, b=6.538(3) Å, c=17.322(8) Å), (Rh1/9W8/9O3)12(PO2)4 and (Rh2/21W19/21O3)14(PO2)4. Single‐crystals of the mixed‐metal (Rh,W)‐MPTBs at m=4 and at m=7 were grown by chemical vapor transport (CVT). Their crystal structures have been refined from X‐ray single‐crystal data {(Rh,W)‐MPTB atm=4: P212121, Z=1, a=5.2232(3) Å, b=6.4966(3) Å, c=17.3819(9) Å, R1=0.032, wR2=0.075 for 1714 unique reflections, 1524 with Fo>4σ(Fo), 66 variables, 1 constraint, composition from refinement (Rh0.15W0.85O3)8(PO2)4; (Rh,W)‐MPTB atm=7: P21/n, Z=1, a=5.2510(4) Å, b=6.4949(5) Å, c=26.685(2) Å, β=90.30(1)°, R1=0.060, wR2=0.163 for 2074 unique reflections, 1894 with Fo>4σ(Fo), 100 variables, comp. from ref. (Rh0.07W0.93O3)14(PO2)4}. These structure refinements show unexpected distribution of Rh and W over the available metal sites. Further characterization (powder reflectance and magnetic measurements) of the (Rh,W)‐MPTB at m=4 and at m=7 suggest for both phases a homogeneity range with respect to the Rh/W ratio and the presence of small amounts of W5+ besides Rh3+ and W6+. Results of the ligand field analysis for the reference material Rh(PO3)3, which is containing the octahedral chromophore [RhIIIO6], are reported (Δo=23200 cm−1, B=490 cm−1). [ABSTRACT FROM AUTHOR]

The solid-state chemistry of coordination complexes has become an actively developing research area of modern inorganic chemistry. Herein, Zn and Hg coordination compounds containing a N,N′-bidentate chelating Schiff-base ligand were synthesized and then characterized using spectroscopic techniques and single-crystal X-ray crystallography. The molecular structures and crystal packing modes of these complexes, as well as the crystal structures of related compounds, were investigated thoroughly using geometrical and Hirshfeld surface analyses, as well as theoretical calculations. It has been revealed that the supramolecular architecture of these series of coordination complexes is governed mainly by a combination of chelate···π and π···π stacking, and non-classical hydrogen bonding interactions. This study provides further insight into the understanding of the coordination chemistry of group IIB complexes containing Schiff-base ligand and the role of weak non-covalent interactions in the solid-state structure of coordination compounds. [ABSTRACT FROM AUTHOR]

Herein we present the first solid‐state structures of tetraiododiborane(4) (B2I4), which was long believed to exist in all phases as discrete molecules with planar, tricoordinate boron atoms, like the lighter tetrahalodiboranes(4) B2F4, B2Cl4, and B2Br4. Single‐crystal X‐ray diffraction, solid‐state NMR, and IR measurements indicate that B2I4 in fact exists as two different polymeric forms in the solid state, both of which feature boron atoms in tetrahedral environments. DFT calculations are used to simulate the IR spectra of the solution and solid‐state structures, and these are compared with the experimental spectra. [ABSTRACT FROM AUTHOR]

The synthesis of [Au{S=C(NH2)2}2][SO3Me] (1) (a) by the anodic oxidation of gold metal in an anolyte of thiourea and methansulfonic acid and (b) by the reaction of Au(OH)3 with an aqueous solution of methanesulfonic acid in the presence of thiourea is reported. The structure of 1 in the solid state has been determined by single-crystal X-ray diffraction showing a linear S–Au–S unit with the thiourea ligands in a leaflet structure folded by 113.2(3)°. The cation of complex 1 is a dimer, based on short S · · · C interactions between two adjacent mononuclear cations. The thermal decomposition behavior of 1 was studied by TG and TG-MS confirming that it decomposes under inert gas or oxygen atmosphere in four steps in the temperature range of 200–650°C. Initial decomposition starts with the release and fragmentation of one of the thiourea ligands, followed by the anion degradation. Powder X-ray diffraction studies specified the formation of gold metal. Based on this observation, complex 1 was used as precursor for the formation of gold nanoparticles (Au NPs) in 1-hexadecylamine (c = 4.0 mol L−1) at T = 330°C without any addition of reducing agents. TEM, electron diffraction, and UV/Vis spectroscopy studies were carried out. Au NPs of size 15 ± 4 nm were formed, showing the characteristic surface plasmon resonance at 528 nm. [ABSTRACT FROM AUTHOR]

The synthesis, chemical and physical properties of [{AgO2CCH2OMe}n] (1) and [{AgO2CCH2OMe(PPh3)}n] (2) are reported. Consecutive reaction of AgNO3 with HO2CCH2OMe gave 1, which upon treatment with PPh3 produced 2. Coordination compound 2 forms a 1D coordination polymer in the solid state as evidenced by single crystal X-ray structure analysis. The coordination geometry at Ag+ is of the [3 + 1] type, whereby the carboxylate anions act as bridging ligands. The formation of PPh3–Ag(I) coordinative bonds results in distorted T-shaped AgPO2 units, which are stabilized further by an additional O–Ag dative bond. TG and TG–MS measurements show that 1 and 2 decompose at 190–250 °C (1) and 260–300 °C (2) via decarboxylation, involving Ag–P (2), C–C and C–O bond cleavages to give elemental silver as confirmed by PXRD studies. In order to verify if polymeric 2 is suitable as a FEBID precursor for silver deposition, its vapor pressure was determined (p170 °C = 5.318 mbar, ∆Hvap = 126.1 kJ mol−1), evincing little volatility. Also EI and ESI mass spectrometric studies were carried out. The dissociation of the silver(I) compound 2 under typical electron-driven FEBID conditions was studied by DFT (B3LYP) calculations on monomeric [AgO2CCH2OMe(PPh3)]. At an energy of the secondary electrons up to 0.8 eV elimination of PPh3 occurs, giving Ag+ and O2CCH2OMe−. Likewise, by release of PPh3 from [AgO2CCH2OMe(PPh3)] the fragment [AgO2CCH2OMe]− is formed from which Ag+ and O2CCH2OMe− is generated, further following the first fragmentation route. However, at 1.3 eV the initial step is decarboxylation giving [AgCH2OMe(PPh3)], followed by Ag–P and Ag–C bond cleavages.

Graphical abstract Highlights • Synthesis and characterization of iron(III) β-diketonate complexes [Fe(β-diketonate) 3 ]. • Their use as MOCVD precursor for Fe 2 O 3 thin film formation. • Single crystal X-ray structure determination of two samples. Abstract Complexes [Fe(β-diketonate) 3 ] (β-diketonate = 2-acetylcyclopentanoate (3a), = 2-acetylcyclohexanoate (3b), = 4,4-dimethyl-1-phenyl pentanedionate (3c)) were synthesized by the reaction of FeCl 3 with the respective β-diketones in presence of NaOH. The molecular structures of 3a and 3c in the solid state are discussed, confirming an octahedral coordination sphere at Fe(III) setup by the three bidentate-bonded β-diketonato ligands. Variation of the β-diketonato ligands allowed to influence the thermal behavior and vapor pressure of the complexes. TG-MS (= Thermo Gravimetry-Mass Spectrometry) studies, exemplarily carried out on 3a , confirmed the release of the β-diketonate ligands. Complexes 3a – c were applied as MOCVD (=Metal-Organic Chemical Vapor Deposition) precursors for the deposition of Fe 2 O 3 thin films on silicon substrates. It was found that with 3a , b , conformal and dense carbon-free γ- and α-Fe 2 O 3 layers were produced at 450 °C, which was verified by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray photon spectroscopy. [ABSTRACT FROM AUTHOR]

The synthesis of FcC(O)CH(R)C(O)Fc (Fc = Fe(η5-C5H4)(η5-C5H5); R = H, 5; nBu, 7; CH2CH2(OCH2CH2)2OMe, 9), [M(κ2O,O′-FcC(O)CHC(O)Fc)n] (M = Ti, n = 3, 10; M = Fe, n = 3, 11; M = BF2, n = 1, 12), and 1-R′-3,5-Fc2-cC3HN2 (R′ = H, 13; Me, 14; Ph, 15) is discussed. The solid-state structures of 5, 7, 9, 12, 13, 15, and 16 ([TiCl2(κ2O,O′-PhC(O)CHC(O)Ph)2]) show that 7 and 9 exist in their β-diketo form. Compound 13 crystallizes as a tetramer based on a hydrogen bond pattern, including one central water molecule. The electrochemical behavior of 5–7 and 9–16 was studied by cyclic and square-wave voltammetry, showing that the ferrocenyls can separately be oxidized reversibly between −50 and 750 mV (5–7, 9, 12–15: two Fc-related events; 10, 11: six events, being partially superimposed). For complex 10, Ti-centered reversible redox processes appear at −985 (TiII/TiIII) and −520 mV (TiIII/TiIV). Spectro-electrochemical UV-Vis/NIR measurements were carried out on 5, 6, and 12, whereby only 12 showed an IVCT (intervalence charge-transfer) band of considerable strength (νmax = 6250 cm−1, Δν½ = 4725 cm−1, εmax = 240 L·mol−1·cm−1), due to the rigid C3O2B cycle, enlarging the coupling strength between the Fc groups.

The copper(II) polypyridyl complex [Cu(pyterpy)2](ClO4)2 (3) (pyterpy = 4′-(4-pyridyl)-2,2′:6,2″-terpyridine) was prepared by the reaction of pyterpy (1) with stoichiometric amounts of [Cu(ClO4)2·6H2O] (2). The progress of the reaction was controlled by FT-IR and UV–vis spectroscopy. The title complex crystallized in the tetragonal space group I4(1)/a with unit cell dimensions of a = 8.6277(1), b = 8.6277(1), c = 57.6398(10) Å, V = 4290.55(12) Å3, and Z = 4. The structure of 3 in the solid-state consists of discrete [Cu(pyterpy)2]+ ions with copper(II) in a distorted octahedral environment setup by two meridional coordinated tripodal 4′-(4-pyridyl)-2,2′:6,2″-terpyridine ligands of which the pyridyl unit stays free. Face-to-face π-interactions between terminal coordinated terpy C5N rings link adjacent [Cu(pyterpy)2]2+ units resulting in the formation of a 2D-polymer. The geometrical-to-geometrical centroid distance (d) is 3.568 Å.

Graphical abstract Ten Pd(0) complexes stabilized by bis-carbene and electron-withdrawing olefin ligands were synthesized and characterized. It was shown that the less efficient deactivated olefin capable of stabilizing the complexes bearing strong σ-donating bis-carbene species was dimethylfumarate. Abstract We have synthesized several novel palladium(0) olefin complexes stabilized by strong σ-donating bis-chelating carbene ligands characterized by one or two CH 2 spacers and electron-withdrawing olefins. Although it appears obvious that the σ-donating carbenes and electron-withdrawing olefins should cooperate in the stabilization of the ensuing complexes, the limit of their coexistence was not hitherto clear. On the basis of previously measured stabilizing capability of the olefins toward Pd(0) complexes we were able to synthesize ten complexes (nine new and one synthesized by a different protocol from that of the literature). The less electron-withdrawing olefin capable of stabilizing the complex was dimethylfumarate. However, the most interesting results were obtained with the (Z)-1,2-bis(p-tolylsulfonyl)ethene (cis -sulf) which instantly isomerizes upon coordination and in the case of the derivative bearing the olefin tetramethyl ethene-1,1,2,2-tetracarboxylate (tmetc) whose decomposition in CD 2 Cl 2 yields the saturated tetramethyl ethane-1,1,2,2-tetracarboxylate (D 2). The solid-state structure of the complex 4d bearing the bis-carbene 1,1′-dibenzyl-3,3′methylenediimidazol-2,2′-diylidene and the olefin (E)-1,2-bis(p-tolylsulfonyl)ethene (trans -sulf) was also determined. [ABSTRACT FROM AUTHOR]

( E )-(5,5-Dimethyl-1,4-diferrocenylhex-2-yn-1-ylidene)(2,4,6-tri- tert -butylphenyl) phosphine ( 3 ) was obtained in the reaction of 2,4,6-tri- tert -butylphenyl phosphine ( 1 ) with 1,4-diferrocenyl butadiyne ( 2 ) in minor yields. Compound 3 was structurally characterized by single crystal X-ray diffraction. The molecular structure of 3 consists of a linear butyne C 4 backbone, which is in conjugation with a phosphene moiety resulting in the phosphapent-2-yn-4-ene motif with one ferrocenyl substituent bonded to a C sp3 and the other one to the C sp2 carbon atom. Both sandwich moieties are located at the same site of the C 4 axis opposing the tert -butyl groups. This results in an alternated stacking within the crystal packing along [0 1 0] with weak T -shaped π interactions within the ferrocenyl containing layer. Electrochemical measurements revealed two reversible redox events for the two ferrocenyl groups at −20 mV and at 135 mV. [ABSTRACT FROM AUTHOR]

Abstract: The structure of Cs3RESi6O15, where RE=Dy–Lu, Y, In, is unusual in that it contains octahedrally coordinated rare‐earth ions; their relative orientation dictates the structure, as they rotate about the c‐axis supported by the cyclic Si6O15 framework. The repeat unit of the rotation is eight units generating a very long (ca. 57 Å) unit cell axis. This unusual repeat unit is created by the structural flexibility of the hexasilicate ring, which is in turn affected by the size of the rare earth ion as well as the size of alkali ion residing within the silicate layers. Previous work showed for the smaller Sc3+ ion, the rotation of the octahedra is not sufficient to achieve closure at an integral repeat unit and an incommensurate structure results. The products are prepared as large, high quality single crystals using a high‐temperature (650 °C) hydrothermal method with CsOH and F− mineralizers. The presence of fluoride is essential to the formation of the product. [ABSTRACT FROM AUTHOR]

The effect of ethylene content, in a range between 8 and 11 mol%, and distribution on the solid‐state morphology of five impact polypropylene copolymers (IPC) have been studied via SEM, fractionation and microstructural characterization via gel permeation chromatography (GPC), high‐temperature thermal‐gradient interaction chromatography (HT‐TGIC), and differential scanning calorimetry (DSC). All copolymers display heterophasic morphology, with rubbery droplets randomly distributed in a predominant iPP matrix. While the mass fraction of amorphous ethylene‐propylene rubber molecules is very similar for all IPC studied, the size of the droplets increases from 0.6 to 1.1 μm with increasing ethylene content. This change in droplet size is correlated with changes in the composition of the crystalline ethylene‐propylene (CEP) component extracted via fractionation. [ABSTRACT FROM AUTHOR]

A series of 11 new pentacene derivatives has been synthesized, with unsymmetrical substitution based on a trialkylsilylethynyl group at the 6-position and various aryl groups appended to the 13-position. The electronic and physical properties of the new pentacene chromophores have been analyzed by UV–vis spectroscopy (solution and thin films), thermoanalytical methods (DSC and TGA), cyclic voltammetry, as well as X-ray crystallography (for 8 derivatives). X-ray crystallography has been specifically used to study the influence of unsymmetrical substitution on the solid-state packing of the pentacene derivatives. The obtained results add to our ability to better predict substitution patterns that might be helpful for designing new semiconductors for use in solid-state devices.

This article presents a comprehensive review of the structures of the known structurally characterized transition metal (M) pnictide (E = P, As) compounds. These compounds are being widely studied for a range of important applications including magnetic materials, magnetocaloric effects, electric conductivity, and superconductivity in addition to high catalytic activities for reactions such as hydrodesulfurization, hydrodenitrogenation, and water splitting. A number of the M x E y combinations are found in mineral form, including meteorites. There is tremendous diversity in this class of compounds, with examples from early to late transition metals being observed having metal to main group element ratios (M:E) ranging from 7.5:1 to 1:10. The review covers 231 M:E stoichiometries crystallizing in 289 different crystal lattices. Compounds with high phosphorus or arsenic content show interesting catenated structures ranging from simple E n units ( E = 2–4), pyramidal P(P) 3 groups, and P 6 rings to more complex branched chains, ribbons and 2-dimensional networks. [ABSTRACT FROM AUTHOR]

We have investigated the ground state properties of buckled GaAs monolayer using density functional theory (DFT) and quantum Monte Carlo (QMC) method. Standard first-principles approaches such as DFT with approximate exchange-correlation functionals do not describe the correlation effect accurately and hence, usually cannot predict results within the chemical accuracy. In order to accurate evaluation of correlation energy that makes a small but very important contribution to the total energy of an electronic system, the quantum Monte Carlo methods are used which include the correlation effect of electron-electron using Jastrow function. We found QMC energies are few tenths eV lower than the DFT energies and the buckled GaAs monolayer have direct the band gap of 1.46 eV within DFT calculations, whereas quasiparticle gap is 3.4(8) eV within QMC calculations. We have also calculated the electron affinity and ionization potential as a function of system size. [ABSTRACT FROM AUTHOR]

In the present work, we have systematically studied structural, electronic and optical properties of buckled GaAs bilayer with and without spin-orbit coupling by density functional theory. Buckled GaAs bilayer have direct band gap of 0.70 eV at high symmetric Г-point which is low as compare to GaAs monolayer. Optical properties such as real and imaginary part of dielectric functions, refractive index, extinction coefficient, absorption spectrum and reflectivity are well studied using density function theory. The calculated optical properties show that the buckled GaAs bilayer can be beneficial for optoelectronic and light emitting devices. [ABSTRACT FROM AUTHOR]

Complex formation processes of the (O,N) donor ligands 6-methylpicolinic acid (6-Mepic), quinoline-2-carboxylic acid (2-QA) and 3-isoquinolinecarboxylic acid (3-iQA) with the organometallic moiety (η 5 -pentamethylcyclopentadienyl)rhodium(III) (RhCp*) were studied in aqueous solution by the combined use of pH-potentiometry, 1 H NMR spectroscopy and UV-Vis spectrophotometry. The solid phase structures of the [RhCp*(L)Cl] complexes bearing 6-Mepic and 2-QA were characterized by single-crystal X-ray diffraction analysis. Studies revealed the exclusive formation of mono complexes of the form [RhCp*(L)(H 2 O)] + (L = deprotonated form of the ligands) and [RhCp*(L)(OH)]. The positively charged aqua species predominate at physiological pH even in the micromolar concentration range. The H 2 O/Cl − co-ligand exchange constants showed that all complexes preferably retain the chlorido ligand at the third coordination site at chloride ion concentrations present in the serum. In addition in vitro cytotoxicity of these [RhCp*(L)Cl] complexes was evaluated in three human cancer cell lines (A549, SW480 and CH1/PA-1) where they showed minor cytotoxic potency. [ABSTRACT FROM AUTHOR]

A series of ferrocenyloxysilanes of type Si(OFc) n R 4-n (Fc = Fe(η 5 –C 5 H 4 )(η 5 –C 5 H 5 ); R = Me: 2 , n = 1; 3 , n = 2; 4 , n = 3; 5 , n = 4. R = Ph: 6 , n = 2) and 1,3–dioxa–2–dimethylsila–[3]ferrocenophane ( 8 ) have been synthesized by the reaction of FcOH ( 1 ) or Fe(η 5 –C 5 H 4 OH) 2 ( 7 ) with the respective chlorosilanes SiCl n R 4-n . Treatment of 6 with Ag[B(C 6 F 5 ) 4 ]·Et 2 O resulted in the formation of [Fe(η 4 –C 5 H 4 (=O))(η 5 –C 5 H 5 )][B(C 6 F 5 ) 4 ] ( 9 ). The molecular structures of 1 – 6 , 8 and 9 in the solid state are reported. The electrochemical behavior of 2 – 6 and 8 was investigated by cyclic (CV) and square wave voltammetry. Ferrocenyloxysilane 3 shows two separated redox events at E 1 °' = −125 mV (Δ E p = 62 mV) and E 2 °' = 80 mV (Δ E p = 60 mV) during the first three cycles. However, in multi-cyclic experiments it decomposes. This differs from 4 and 5 because these compounds decompose more rapidly. Compared to 3 , compound 6 ( E 1 °' = −125 mV (Δ E p = 59 mV), E 2 °' = 55 mV (Δ E p = 62 mV)) in which Ph units are present is more stable towards electrochemical oxidation. The electron-donating OSiMe 3 group in 2 leads to a significant cathodic shift of the redox potential ( E °' = −165 mV) as compared with FcH. In contrast, ferrocenophane 8 possesses a reversible redox event at E °' = 10 mV (Δ E p = 66 mV). Exemplarily, spectroelectrochemical UV-Vis/NIR studies were carried out on 6 indicating significant electrostatic interaction among the two ferrocenyloxy groups as oxidation progresses. [ABSTRACT FROM AUTHOR]

Two novel half-sandwich Ti complexes, both incorporating two adamantoxy (OAd) ligands coordinated to their central atoms were synthesized. The complexes were characterized by 1 H, 13 C, 19 F NMR, EI-MS and IR spectroscopy and by single-crystal X-ray diffraction. In both complexes, the coordination environment is pseudo-tetrahedral and is assembled of two O-coordinated adamantoxy and one η 5 -coordinated permethylcyclopentadienyl ligand. The fourth ligand in complex 1 is a methyl group coordinated through a regular σ-bond, whereas in complex 2 the same coordination site is occupied by the methyl group of the balancing (C 6 F 5 ) 3 BMeˉ anion. DFT computations complemented with NBO analyses of 2 have unveiled, that in addition to the electrostatic interactions occurring between the half-sandwich titanocene moiety and the anionic ligand, delocalization of one methyl C H bond into the available acceptor orbital on the central atom takes place. AIM analyses of 2 have revealed the presence of a Bond Critical Point between the metal atom and the anionic methyl group. These results prove foundation for the description of 2 as a zwitterionic complex coupled with a concurrent Ti⋯C H agostic interaction in its molecule. The comparison of 2 with its analogous complex equipped with two O t -Bu ligands instead of both OAd has suggested only a minor change in the extent of the agostic interaction, despite significant geometric differences between the two complexes. [ABSTRACT FROM AUTHOR]

The control of the glass transition temperature ( Tg) of methacrylic acid-styrene terpolymers with n-butyl methacrylate (BMA) is scoped to assess their potential to alter the thermal transitions of boron subphthalocyanine (BsubPc)-containing polymers. The change in kinetics and physical properties of the terpolymers are observed under different synthetic and process conditions such as varying molar feed of BMA, addition of 1,4-dioxane solvent, reaction time, concentration of N-tert-butyl- N-(1-diethylphosphono-2,2-dimethylpropyl) nitroxide (SG1) mediator and initiator type to find the optimal conditions. Four terpolymers are then coupled to BsubPc using the established process. Differential scanning calorimetry analysis shows that the backbone polymer composition has little effect on the Tg of the poly-BsubPcs. Solid-state fluorescence spectroscopy reveals that after annealing the films at temperatures higher than the Tg, BsubPc aggregates are formed and, therefore, the arrangement of the polymers is dominated by the BsubPc moiety and its self-aggregation. [ABSTRACT FROM AUTHOR]

Li18P6N16 was synthesized by reaction of LiPN2 and Li7PN4 at 5.5 GPa and 1273 K employing the multi-anvil technique. It is the first lithium nitridophosphate obtained by high-pressure synthesis. Moreover, it is the first example received by reaction of two ternary lithium nitrides. The combination of high-pressure conditions with a Li3N flux enabled a complete structure determination using single-crystal X-ray diffraction. The hitherto unknown tricyclic [P6N16]18− anion is composed of six vertex-sharing PN4 tetrahedra forming one vierer- and two additional dreier-rings. To confirm the structure, Rietveld refinement, 7Li and 31P solid-state NMR spectroscopy, FTIR spectroscopy and EDX measurements were carried out. To validate the ionic properties, the migration pathways of the Li+ ions were evaluated, and the conductivity and its temperature dependence were determined by impedance spectroscopy measurements. In order to obtain a clearer picture of the formation mechanism of this compound class, different synthetic approaches were compared, enabling targeted syntheses of unprecedented P/N-anion topologies with intriguing properties. [ABSTRACT FROM AUTHOR]

Cp C H is a chiral cyclopentadienide-type ligand consisting of a CpH core with two annulated dibenzocycloheptatriene wings. Due to the presence of the seven-membered rings, the wings are bent making Cp C H a novel, intrinsically chiral CpH derivative. Starting from ClTi(O i Pr) 3 and (Cp C ) - , obtained by deprotonation of Cp C H with BuLi, the titanium (IV) half-sandwich complex (Cp C )Ti(O i Pr) 3 was obtained. Further treatment of (Cp C )Ti(O i Pr) 3 with an excess of Me 3 SiI gave the iodo derivative (Cp C )Ti(O i Pr)I 2 in good yields. Both complexes could structurally be characterized by means of single crystal X-ray crystallography. Direct conversion of (Cp C ) - with TiCl 4 resulted in oxidation of the anionic ligand and thus formation of the C C bridged dimer (Cp C ) 2 . [ABSTRACT FROM AUTHOR]

The structural characterisation (X-ray diffraction) of a series of anionic antimony (III) and bismuth (III) halide complexes containing protonated 2-methyl-1,3-benzoxazole (boxH) countercations are reported. Treatment of aqueous strong acid (HCl or HBr) or strong acid/additional solvent mixtures of box with MX 3 (M = Sb, Bi; X = Cl, Br) leads to the isolation of known compounds BiCl 5 (boxH) 2 (6 : 33%) and SbBr 5 (boxH) 2 (7 : 31%) and the novel material BiBr 5 (boxH) 2 (8 : 57%). In the solid state, 6 – 8 all display an anionic portion consisting of edge sharing infinite zig-zag chains of the metallic [(MX 5)2–] ∞ units classified as Type A in structure. In contrast, mixtures of box, conc. HCl and SbCl 3 yield, following recrystallization, to small quantities of Sb 2 OCl 6 (boxH) 2 (2 : 0.4%); a hitherto unknown complex containing the less common Sb 2 OCl 6 2− anion. Hypotheses as to the origin of 2 are presented including its formation by hydrolysis of known SbCl 4 (boxH). Hydroiodic acid solutions of box treated with SbI 3 leads to the isolation of the SbI 6 (boxH) 3 ·(H 2 O) (9 : 42%) which displays a rare example of the isolated SbI 6 3− anion. The treatment BiI 3 under similar conditions leads to the precipitation of previously known Bi 2 I 9 (boxH) 3 (10 : 54%) as a major product. Further evaporation of the reaction mixture from which 10 was obtained yields a second minor product, 11 (3%), identified as the Bi analogue of 9 : BiI 6 (boxH) 3 ·(H 2 O). The species described herein are further discussed in terms of their general coordination properties and relevance to related complexes under current scrutiny for their solid-state materials properties. Solid-state examples of the title complexes are reported. [Display omitted] · Second known unequivocal example of a SbI 6 3− containing complex. · First solid-state characterisation of any members of the Sb/Bi halido benzoxazolium series. · Isolation of a rare example of a material with the Sb 2 OCl 6 2− anion. [ABSTRACT FROM AUTHOR]

Two planarized analogues of the prototypical Blatter radical ( 1), peri-annulated 1S and 1O, are demonstrated and provide a new platform for molecular and supramolecular engineering, and for tuning electronic and magnetic properties of the radical. Planarization of 1 results in bathochromic shift to the near-IR region, greater spin delocalization, and anodic shift of the reduction potential only for 1S. Magnetization studies revealed nearly ideal paramagnetic behavior at high temperatures for both radicals 1S and 1O with one-dimensional ferromagnetic interaction in the former (2 J=14.4 cm−1) and antiferromagnetic interactions in 1O at low temperatures. [ABSTRACT FROM AUTHOR]

It is shown that UVO2+ ions can reside at UVIO22+ lattice sites during mild reduction and crystallization process under solvothermal conditions, yielding a complicated and rare mixed-valent uranium phosphonate compound that simultaneously contains UIV, UV, and UVI. The presence of uranium with three oxidation states was confirmed by various characterization techniques, including X-ray crystallography, X-ray photoelectron, electron paramagnetic resonance, FTIR, UV/Vis-NIR absorption, and synchrotron radiation X-ray absorption spectroscopy, and magnetism measurements. [ABSTRACT FROM AUTHOR]

It is shown that UVO2+ ions can reside at UVIO22+ lattice sites during mild reduction and crystallization process under solvothermal conditions, yielding a complicated and rare mixed-valent uranium phosphonate compound that simultaneously contains UIV, UV, and UVI. The presence of uranium with three oxidation states was confirmed by various characterization techniques, including X-ray crystallography, X-ray photoelectron, electron paramagnetic resonance, FTIR, UV/Vis-NIR absorption, and synchrotron radiation X-ray absorption spectroscopy, and magnetism measurements. [ABSTRACT FROM AUTHOR]

A convenient synthesis of 1,2-dicyanoferrocene ( 3) was developed by using 2,4-dinitrofluorobenzene as a dehydrating agent for the treatment of 1,2-ferrocenedicarbaldehyde dioxime ( 2) to give 3 in yields exceeding 80%. Compounds 2 and 3 have been characterized by IR and NMR (1H, 13C{1H}) spectroscopy and by electrochemistry (cyclic voltammetry and square-wave voltammetry). Furthermore, the molecular structures of 2 and 3 in the solid state have been determined by single-crystal X-ray crystallographic studies. [ABSTRACT FROM AUTHOR]

1,1′-Dinitramino-5,5′-bitetrazole and 1,1′-dinitramino-5,5′-azobitetrazole were synthesized for the first time. The neutral compounds are extremely sensitive and powerful explosives. Selected nitrogen-rich salts were prepared to adjust sensitivity and performance values. The compounds were characterized by low-temperature X-ray diffraction, IR and Raman spectroscopy, multinuclear NMR spectroscopy, elemental analysis, and DTA/DSC. Calculated energetic performances using the EXPLO5 code based on calculated (CBS-4M) heats of formation and X-ray densities support the high performances of the 1,1′-dinitramino-5,5′-bitetrazoles as energetic materials. The sensitivities toward impact, friction, and electrostatic discharge were also explored. Most of the compounds show sensitivities in the range of primary explosives and should only be handled with great care! [ABSTRACT FROM AUTHOR]

ABSTRACT To obtain novel low-bandgap materials with tailored hole-transport properties and extended absorption, electron rich 3,4-ethylenedioxythiophene is introduced as a comonomer in diketopyrrolo[3,4- c]pyrrole copolymers with different aryl flanking units. The polymers are characterized by absorption and photoluminescence spectroscopy, dynamic scanning calorimetry, cyclic voltammetry, and X-ray diffraction. The charge transport properties of these new materials are studied carefully using an organic field effect transistor geometry where the charge carriers are transported over a narrow channel at the semiconductor/dielectric interface. These results are compared to bulk charge carrier mobilities using space-charge limited current (SCLC) measurements, in which the charge carrier is transported through the complete film thickness of several hundred nanometers. Finally, charge carrier mobilities are correlated with the electronic structure of the compounds. We find that in particular the thiophene-flanked copolymer PDPP[T]2-EDOT is a very promising candidate for organic photovoltaics, showing an absorption response in the near infrared region with an optical bandgap of 1.15 eV and a very high bulk hole mobility of 2.9 × 10−4 cm2 V−1 s−1 as measured by SCLC. This value is two orders of magnitudes higher than SCLC mobilities reported for other polydiketopyrrolopyrroles and is in the range of the well-known hole transporting polymer poly(3-hexylthiophene). © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 639-648 [ABSTRACT FROM AUTHOR]

ABSTRACT The Sonogashira-Hagihara coupling polymerization of d-hydroxyphenylglycine-derived diiodo monomers 1-4 and platinum-containing diethynyl monomer 5 gave the corresponding polymers [poly( 1-5)-( 2-5)] with number-average molecular weights of 19,000-25,000 quantitatively. The polymers were soluble in CHCl3, CH2Cl2, THF, and DMF. CD and UV-vis spectroscopic analysis revealed that amide-substituted polymers [poly( 1-5) and poly( 2-5)] formed chiral higher-order structures in solution, while ester-substituted polymers [poly( 3-5) and poly( 4-5)] did not. Poly( 1-5) formed one-handed helices in THF/toluene mixtures, while it formed chiral aggregates in THF/MeOH mixtures. Poly( 1-5) emitted fluorescence with quantum yields ranging from 0.8 to 1.3%. The polymers usually aggregated in the solid state. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2452-2461 [ABSTRACT FROM AUTHOR]

The copper(II) polypyridyl complex [Cu(pyterpy)2](ClO4)2 (3) (pyterpy = 4'-(4-pyridyl)-2,2':6,2?-terpyridine) was prepared by the reaction of pyterpy (1) with stoichiometric amounts of [Cu(ClO4)2·6H2O] (2). The progress of the reaction was controlled by FT-IR and UV-vis spectroscopy. The title complex crystallized in the tetragonal space group I4(1)/a with unit cell dimensions of a = 8.6277(1), b = 8.6277(1), c = 57.6398(10) Å, V = 4290.55(12) ų, and Z = 4. The structure of 3 in the solid-state consists of discrete [Cu(pyterpy)2]+ ions with copper(II) in a distorted octahedral environment setup by two meridional coordinated tripodal 4'-(4-pyridyl)-2,2':6,2?-terpyridine ligands of which the pyridyl unit stays free. Face-to-face p-interactions between terminal coordinated terpy C5N rings link adjacent [Cu(pyterpy)2]2+ units resulting in the formation of a 2D-polymer. The geometrical-to-geometrical centroid distance (d) is 3.568 Å. [ABSTRACT FROM AUTHOR]