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The establishment of a simple molecular design strategy to realize red-shifted emission while maintaining good color purity for multi-resonance induced thermally activated delayed fluorescent (MR-TADF) materials remains an appealing yet challenging task. Herein, we demonstrate that the attachment of a cyano (CN) functionality at the lowest unoccupied molecular orbital location of the MR-TADF skeleton can promote attractive red-shifted emission due to the exceptional electron-withdrawing capacity of the CN group, which represents the first example of orange–red MR-TADF emitters. Meanwhile, the linear CN group adopts a coplanar conformation with the MR-framework to restrict structure relaxation associated with rotation, which is beneficial to maintain a small full-width at half-maximum and thus a good color purity. The CNCz-BNCz-based OLED device, which utilizes a TADF sensitized mechanism to accelerate the up-conversion process of triplet excitons in the emitting layer, exhibits an outstanding external quantum efficiency (EQE) as high as 33.7%, representing the state-of-the-art performance for orange–red TADF-OLEDs., The first example of narrowband orange–red MR-TADF emitters has been developed, which realizes a record-high EQE of 33.7% in OLEDs.

A series of organometallic complexes [Cl(dppe)2 Ru-C≡C-(3-R-C4 H2 S)-C≡C-Ru(dppe)2 Cl] (3-R-C4 H2 S=3-substituted thienyl moiety; R=-H, -C2 H5 , -C3 H7 , -C4 H9 , -C6 H13 , -OMe, -CN in 5 a-5 g respectively) have been synthesized by systematic variation of 3-substituents at the thienylethynyl bridging unit. The diruthenum(II) wire-like complexes (5 a-5 g) have been achieved by the reaction of thienylethynyl bridging units, HC≡C-(3-R-C4 H2 S)-C≡CH (4 a-4 g) with cis-[Ru(dppe)2 Cl2 ]. The wire-like diruthenium(II) complexes undergo two consecutive electrochemical oxidation processes in the potential range of 0.0 - 0.8 V. Interestingly, the wave separation between the two redox waves is greatly influenced by the substituents at the 3-position of the thienylethynyl. Thus, the substitution on 3-position of the thienylethynyl bridging unit plays a pivotal role for tuning the electronic properties. To understand the electronic behavior, density functional theory (DFT) calculations of the selected diruthenium wire-like complexes (5 a-5 e) with different alkyl appendages are performed. The theoretical data demonstrate that incorporation of alkyl groups to the thienylethynyl entity leaves unsymmetrical spin densities, thus affecting the electronic properties. The voltammetric features of the other two Ru(II) alkynyl complexes 5 f and 5 g (with -OMe and -CN group respectively) show an apparent dependence on the electronic properties. The electronic properties in the redox conjugate, (5 a+ ) with Kc of 3.9×106 are further examined by UV-Vis-NIR and FTIR studies, showing optical responses in NIR region along with changes in "-Ru-C≡C-" vibrational stretching frequency. The origin of the observed electronic transition has been assigned based on time-dependent DFT (TDDFT) calculations.

A series of cyano-substituted stilbene derivatives exhibit quenched fluorescence in solution, in sharp contrast to their highly emissive parent counterparts. By employing the polarizable continuum model (PCM) method coupled with thermal vibration correlation function (TVCF) formalism, we comparatively investigated the electronic structures and excited-state dynamics of cyano-substituted para-distyrylbenzene (CN-DSB), 1,2-bis(pyridylphenyl)ethane (CN-BPPE) and the corresponding non-substituted DSB and BPPE lack of the cyano groups at their vinylene moieties in solution. The results show that the non-radiative decay rate constants of the CN-substituents are greatly enhanced by more than 4 orders of magnitude, while the radiative decay rate constants experience slight reduction, resulting in the very tiny fluorescence quantum efficiency. By analyzing the reorganization energies projected onto both normal modes and internal coordinates, the non-radiative consumption ways via molecular torsional motions of the single even double bonds adjacent to the CN group are active upon CN-substitution. Our study presents a rational explanation for the experimental CN-substitution induced quenching phenomena in stilbene derivatives, which is beneficial for the design of new fluorescent emitters and probes.

Difluoromethylation is a straightforward and widely applied strategy used to incorporate HCF2 into organic molecules. In contrast, cyanation reagents are typically volatile or highly toxic, or they require harsh reaction conditions. Incorporation of both CN and HCF2 into organic molecules, such as alkenes, is a worthwhile but challenging task. A method for photocatalyzed cyanodifluoromethylation of alkenes has been developed, which employs a Ph3 P+ CF2 CO2- /NaNH2 (or NH3 ) reagent system. Ph3 P+ CF2 CO2- functions as both the HCF2 and CN carbon source. A cyanide anion is generated in situ under mild conditions, thereby avoiding the use of toxic cyanation reagents. The photocatalytic method permits cyanodifluoromethylation of a range of alkenes under mild room temperature conditions. The CN group within the products may be further derivatized by standard methods.

The supramolecular arrangement of 4-cyanopyridine (4CNpy) in its native crystal form and its co-crystals with halogen bond (XB) donors is discussed in terms of long-range synthon aufbau modules (LSAMs) and energy frameworks. Dissociations of 2D zigzag chains of parent 4CNpy into 1D dimers observed in its co-crystals are in good agreement with the aufbau model. Its co-formers, XB donors 1,4-I2(CF2)4, C2I2, 1,3- and 1,4-I2C6F4 (m- and p-DITFB), provide equal energy of I⋯N XBs, but perfluorinated iodo-alkane 1,4-I2(CF2)4 and diiodoacetylene C2I2 cannot achieve the same strength of homomolecular aggregation as π–π stacking in columnar DITFB modules. As a result, DITFBs form I⋯N XBs with both Npy and NCN nitrogen atoms of 4CNpy, while 1,4-I2(CF2)4 and C2I2 only with the Npy atom. This is not a particular case of 4CNpy co-crystals, but in general, DITFB appears to be a more effective XB donor co-former than C2I2, 1,4-I2(CF2)n and other iodo-XB donors, which has similar potential to an iodine atom but lacks homomolecular aggregation. In supramolecular reactions of p-DITFB with (η6-Ar)RuX2(4CNpy) (Ar = p-cymene, X = Cl, I) bearing Npy-coordinated 4CNpy, the former gives definite preference to the XBs with the halogen atoms, but not to the CN group of the 4CNpy ligand.

The synthesis of new C60 fullerene derivatives functionalized with thiophene moieties as well as with electron donating or electron withdrawing groups, bromine (Br) or cyano (CN), respectively, using Bingel reactions is reported. The synthesized derivatives were used as the electron transporting materials (ETMs) in inverted perovskite solar cells (PSCs). Compared to devices fabricated with [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), the new derivatives showed similar electrochemical properties and electron mobilities. However, PSCs based on the new derivatives synthesized in this work exhibited higher power conversion efficiencies (PCEs) than PC61BM based devices, which were ascribed to their better passivation ability, likely due to specific interactions between the fullerene addend and the perovskite layer surface. Devices based on the fullerene bearing the CN group exhibited an additionally improved efficiency due to the increased dielectric constant (er) of this derivative. These results show that the new functionalized fullerene derivatives can act as efficient ETMs in inverted PSCs.

We synthesized two wide bandgap A–D–A structured p-type organic semiconductor (p-OS) small molecules with weak electron-withdrawing ester end groups: SM1 with cyano group (CN) on the ester group and SM2 without the CN group. SM1 showed stronger absorption, lower-lying HOMO energy level, and higher hole mobility in comparison with that of SM2 without the CN groups. The all-small-molecule organic solar cell (SM-OSC) with SM1 as donor and a narrow bandgap n-OS IDIC as acceptor demonstrated a high power conversion efficiency (PCE) of 10.11% and a high fill factor (FF) of 73.55%, while the PCE of the device based on SM2:IDIC is only 5.32% under the same device fabrication condition. The PCE of 10.11% and FF of 73.55% for the SM1-based device are the highest values for the nonfullerene SM-OSCs reported in the literature so far. The results indicate that the cyano substitution in SM1 plays an important role in improving the photovoltaic performance of the p-OS donors in the nonfullerene SM-OSC. In addition, the ...

Two mixed-valence compounds have been isolated from copper-cyanide-meen systems, Cu4(CN)5meen2 and Cu2(CN)3meen2·H2O, where meen is N-methyl­ethylenedi­amine. The former crystallizes as a polymer, in which CuIImeen2 moieties are covalently linked via cyanide bridges to a three-dimensional CuI cyanide-bridged array, while the latter is a binuclear monomer., The crystal structures of two mixed-valence copper cyanide compounds involving N-methyl­ethylenedi­amine (meen), are described. In compound (I), poly[bis(μ3-cyanido-κ3 C:C:N)tris(μ2-cyanido-κ2 C:N)bis(N-methylethane-1,2-di­amine-κ2 N,N′)tricopper(I)copper(II)], [Cu4(CN)5(C3H10N2)2] or Cu4(CN)5meen2, cyanide groups link CuI atoms into a three-dimensional network containing open channels parallel to the b axis. In the network, two tetra­hedrally bound CuI atoms are bonded by the C atoms of two end-on bridging CN groups to form Cu2(CN)6 moieties with the Cu atoms in close contact at 2.560 (1) Å. Other trigonally bound CuI atoms link these units together to form the network. The CuII atoms, coordinated by two meen units, are covalently linked to the network via a cyanide bridge, and project into the open network channels. In the mol­ecular compound (II), [(N-methylethylenediamine-κ2 N,N′)copper(II)]-μ2-cyanido-κ2 C:N-[bis(cyanido-κC)copper(I)] monohydrate, [Cu2(CN)3(C3H10N2)2]·H2O or Cu2(CN)3meen2·H2O, a CN group connects a CuII atom coordinated by two meen groups with a trigonal–planar CuI atom coordinated by CN groups. The mol­ecules are linked into centrosymmetric dimers via hydrogen bonds to two water mol­ecules. In both compounds, the bridging cyanide between the CuII and CuI atoms has the N atom bonded to CuII and the C atom bonded to CuI, and the CuII atoms are in a square-pyramidal coordination.

Symmetry-breaking charge transfer upon photoexcitation of a linear A-π-D-π-A molecule (D and A being electron donating and accepting groups) could be visualized using ultrafast time-resolved infrared spectroscopy by monitoring the CN stretching modes on the A units. Whereas in apolar solvents, the S1 state remains symmetric and quadrupolar, symmetry breaking occurs within ca. 100 fs in polar solvents as shown by the presence of two CN bands, instead of one in apolar solvents, with a splitting that increases with polarity. In protic solvents, symmetry breaking is significantly amplified by H-bonding interactions, which are the strongest at the CN group with the highest basicity. In strongly protic solvents, the two CN bands transform in about 20 ps into new bands with a larger splitting, and the lifetime of the S1 state is substantially reduced. This is attributed to the formation of an excited asymmetric tight H-bond complex.

A preparative synthetic procedure to the meso-CN substituted BODIPY has been developed. This method is based on the addition of KCN to the borondipyrromethene moiety of the meso-unsubstituted molecules in the presence of a crown ether with further oxidation with Pb(OAc)4. The CN group at this position causes an essential bathochromic shift in absorption/emission and influence on other physicochemical properties of borondipyrromethenes over a wide range.

A series of bridged 2,2-bi(1,3,4-oxadiazole) energetic derivatives were designed and their geometrical structures, electronic structures, heats of formation, detonation properties, thermal stabilities and thermodynamic properties were fully investigated by density functional theory. The results showed that the –N3 group and the –N– bridge play an important role in improving heats of formation of these 2,2-bi(1,3,4-oxadiazole) derivatives. The calculated detonation properties indicated that the –NF2 group and the –N– bridge were very useful for enhancing the heats of detonation, detonation velocities and detonation pressures. Twenty-four compounds were found to possess equal or higher detonation properties than those of RDX, while 14 compounds had equal or higher detonation properties than those of HMX. The analysis of the bond-dissociation energies suggested that the –CN group was the effective structural unit for increasing the thermal stabilities while the –NHNH2 group decreased these values. Overall, taking both the detonation properties and thermal stabilities into consideration, 22 compounds (A4, A6, A8, A9, B4, B9, C2, C3, C4, C5, C7, C, C9 D4, D8, D9, E9, F4, F9, G9, H4 and H9) were selected as the potential candidates for high-energy-density materials.

Coupled oxidation of iron tetraphenylporphyrins bearing either a OMe , Me , F , Cl , COOMe , CF 3 or CN group in the para-position of the phenyl groups gave tetraarylbiladien-ab-1-one and triarylbilindione. The ratios of the yields of the former to those of the latter were linearly correlated with the Hammett substituent constants σp+, with a positive slope (Δρ = 0.64). The Hammett plot of the oxidation rate vs. the substituent constant σp also showed a positive slope (ρ = 0.30). These substituent effects suggest that a nucleophilic step is included in the formation of bilindione. Coupled oxidation of an A3B type tetraarylporphyrin having an electron withdrawing nitro group in one of the phenyl groups indicated that the oxidation leading to biladienone occurred rather statistically in any of the meso-positions, while the oxidation leading to bilindione occurred preferentially in the meso-position bearing the 4-nitrophenyl group.

Achieving complete substrate specificity through multiple interactions like an enzyme is one of the ultimate goals in catalytic studies. Herein, we demonstrate that multiple interactions between the CeO2 surface and substrates are the origin of substrate-specific hydration of nitriles in water by CeO2, which is exclusively applicable to the nitriles with a heteroatom (N or O) adjacent to the α-carbon of the CN group but is not applicable to the other nitriles. Kinetic studies reveal that CeO2 reduces the entropic barrier (TΔS‡) for the reaction of the former reactive substrate, leading to 107-fold rate enhancement compared with the latter substrate. Density functional theory (DFT) calculations confirmed multiple interaction of the reactive substrate with CeO2, as well as preferable approximation and alignment of the nitrile group of the substrate to the active OH group on CeO2 surface. This can lead to the reduction of the entropic barrier. This is the first example of an entropy-driven substrate-specific...

We report that 5-fold twinned nanowires and single twinned right bipyramids of Pd with high yields can be selectively synthesized in a hydrophilic system with the assistance of acetonitrile and ethanol, respectively. The controlled synthesis is based on an idea that small organic molecules (SOMs) that can attract halide ions via electrostatic interactions of different strengths could well adjust their activity to tune the etching degree of O2/halides for protecting the twinned Pd crystal nucleus. We consider that relatively stronger interaction between acetonitrile and halide ions for the formation of nanowires is due to the existence of three C–Hδ+ bonds induced by the electron-withdrawing CN group of CH3CN, which is confirmed by an as-called iodine starch test, 1H nuclear magnetic resonance spectra, and theoretical calculations. On the basis of this finding, we then have successfully expanded SOMs to other molecules, including acetone, 1,4-dioxane, and 1,3,5-trioxane, which have a function similar to th...

Four second-order nonlinear optical chromophores with D–π–A, D–A–π–A and D–D–π–A architectures have been synthesized and systematically characterized. Chromophores A and C have been synthesized with an additional acceptor (–CN) or donor group (thiophene) on the π bridge, termed the D–A–π–A and D–D–π–A configurations. D–π–A structural chromophores B and D were chosen as reference compounds for comparison. The results show that incorporation of the –CN group could increase poling efficiency possibly due to reduced intermolecular dipole–dipole interactions which results in comparable r33 values (48 pm V−1). An r33 value of 45 pm V−1 was obtained for the film C/APC suggesting significant site isolation. Compared with the D–π–A structural chromophores B and D, chromophores A and C demonstrated similar or enhanced NLO effects and better optical transparency.

A series of pyrene sensitizers (PC, PN, PMN, PR) with various electron withdrawing anchoring groups have been synthesized to understand their consequence on the optoelectronic properties. All the sensitizers have been characterized by NMR, mass spectroscopic and IR techniques. Absorption measurements revealed that charge transfer transition was enhanced by introducing electron withdrawing groups. Effect of solvents on the absorption and emission properties of the sensitizers was probed through multi-parameter Catalan solvent scales. Thermal stability of the sensitizers was found to be influenced by the presence of COOH group. DFT/TDDFT calculations were performed to gain insight into the structure and electronic properties of the pyrene sensitizers. To investigate the binding affinity of pyrene sensitizers with TiO2, absorption measurement was performed and the results suggest that the sensitizer having COOH group along with a CN group (PC) show higher binding affinity over other sensitizers containing COOH group (PR) and NO2 group (PN). Further, laser flash photolysis measurement was carried out to study the electron transfer process between the sensitizers and TiO2. Electron injection into the conduction band of TiO2 was confirmed by the detection of cation radical of the sensitizer. We envisage that the results from this work will pave the way to design new efficient sensitizers with predetermined electron withdrawing anchoring groups and their photophysical properties for photovoltaic applications.

The crystal structure of KLaMo(CN)8 · 9H2O was determined from X-ray diffraction data. The crystals are monoclinic, space group P21/c, a = 8.7451(4), b = 25.2761(13), c = 10.6744(5) A, β = 117.059(3)°, V = 2101.22(17) A3, Z = 4, ρ(calcd) = 2.037 g/cm3, R = 0.0242, wR 2 = 0.0500 for 5656 independent reflections. The coordination polyhedra of the Mo, La, and K atoms are the tetragonal antiprism [Mo(CN)8], the monocapped tetragonal antiprism [La(NC)4(OH2)5], and the strongly distorted monocapped trigonal prism [K(NC)3(OH2)4], respectively. The La and K atoms are N-linked by seven bridging cyano groups to form double layers with two sandwiched uncoordinated water molecules and the sandwiched terminal CN group. The complex can be formulated as “[K(H2O)2][La(H2O)5][Mo(CN)8]” n · 2nH2O.

Three molecules with different centers (boron and nitrogen) and peripheral substituted groups [N(CH 3 ) 2 and CN] have been theoretically studied with B3LYP/6-31G(d) associated with ZINDO and sum-over-states methods. The maximum two-photon absorption cross-section δ max of the molecule with boron (B) center and N(CH 3 ) 2 peripheral group is larger than that of the molecule with nitrogen (N) center and N(CH 3 ) 2 peripheral group. As for the two molecules with N center, the δ max is obviously increased with the change from N(CH 3 ) 2 to CN group. This indicates that the large intramolecular charge transfer is in favor of the TPA response.

Recently, p -terphenyls containing alkoxylated backbones with or without CN groups on either the central phenyl ring or peripheral rings were synthesized and their photo-luminescent properties were studied. Herein, semi-empirical AM1 and density functional theory (DFT) B3LYP calculations with the 6-31G* basis set have been performed to optimize structure for the ground state and the semi-empirical ZINDO calculations have been used to determine the maximum absorption ( λ abs max ) and emission wavelengths ( λ emi ) for 19 p -terphenyls. The steric effect is assigned to be responsible for the calculated λ abs max and λ emi shifts and the CN group at the central phenyl with ortho -substitution and at peripheral phenyl rings with para- substitution can also significantly influence these spectra. According to experimental results, the p -terphenyls with CN groups may have a lower energy of LUMO, and thus, we investigated the influence of the substitution position and the number of CN groups on the p -terphenyl moiety. The calculated optical and electronic properties provide important information on the behavior of the corresponding Organic light-emitting diode device (OLED). The suggested theoretical calculation protocol can be employed to predict electro-luminescent characteristics of other materials, and further, to design novel materials for OLED.

Standard Density Functional Theory calculations for two mesogenic species (phenylbenzoate derivatives with the terminal and lateral –CN group) are performed in order to study the interaction between two molecules of each derivative. Two steps investigations are done: for isolated molecules and for pair of molecules for each of derivatives. Results of calculations (involving geometry optimization), which are carried out for isolated species, indicate the similar geometries (except –CN groups position) although different electronic structures of molecules of both derivatives. Examination of the interaction energy of molecule pairs allows one to get their mutual orientation. It is found that for two parallel molecules with terminal –CN group the interaction energy reaches minimum when they are shifted mutually ca. 0.32 nm. On contrary, for two molecules with lateral –CN group the energy minimum is obtained such a mutual geometry in which atoms of both species can be projected to each other; the molecules do ...

A compilation of experimental values of the infinite dilution partial molar Gibbs energy, enthalpy, and heat capacity of hydration together with partial molar volumes in water at 298.15 K and 0.1 MPa is presented for aliphatic nitriles and dinitriles. These data are treated in the framework of the first- and second-order group additivity methods. Thermodynamic properties are determined for the first-order CN group and for the following second-order groups: C-(CN)(C)(H)2, C-(CN)(C)2(H), and CN-(C). The relatively long-range dipole−dipole interactions of two terminal nitrile groups require additional corrections, {CN-(CH2)2-CN}corr and {CN-(CH2)3-CN}corr, for lower dinitriles. New experimental studies of aqueous branched mononitriles and lower dinitriles (particularly propanedinitrile) are required to expand the usefulness and accuracy of group contribution models for aqueous nitriles.

The intramolecular version of nucleophilic additon of phosphites to imines was carried out for the first time taking as an example β-aldiminoalkylphosphites, formed from chlorophosphites and β-aldiminoalcohols [N-(benzylidene)-2-aminoethanol and R-(+)-N-(benzylidene)-2-aminobutanol-1]. In these reactions, stereoisomeric 1,4,2-oxazaphosphorines were obtained in good yields. R-(+)-N-(benzylidene)-2-aminobutanol-1 being used as a precursor, nucleophilic attack by P(III) atom on electrophilic C atom of the CN group proceeds stereospecifically with participation of only re-face of the two possible diastereotopic faces of the imine double bond to give the epimeric at phosphorus (3R,5R)-2-(β-chloroethyl)-2-oxo-3-phenyl-5-ethyl-1,4,2-oxazaphosphorines as precursors of nonracemic α-aminophosphonic acids. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:56–61, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10054

Two cubic (Cub) phase forming compounds, 4ʹ-n-hexadecyloxy-3ʹ-cyanobiphenyl-4-carboxylic acid (ACBC-16) and its 3′-nitro analogue (ANBC-16) were studied by infrared (IR) spectroscopy. In the temperature region of the Cub phase, the molar fraction of hydrogen-bonded COOH groups estimated for ACBC-16 was by ≈0.05 at maximum larger than that for ANBC-16 and the aromatic ring C═C stretching (ν(C═C)ring) band frequency of ACBC-16 was by 3 cm−1 lower than that of ANBC-16. The quantum chemical calculation at DFT/B3LYP level, on the one hand, showed no meaningful difference in the stabilisation energy for dimerisation and the ν(C═C)ring band frequency between the respective model compounds. These results can be ascribed to the different steric effects of the side groups; the CN group would make possible the close contact of neighbouring phenyl rings while the bulky NO2 group would not, giving slightly more stabilised dimerisation of ACBC-16 in the Cub phase than in ANBC-16.

The results of dielectric studies performed in a broad frequency range for two compounds, 4-cyanophenyl 4-n-heptylbenzoate (7BBCN) and 4-(4-cyanobutyloxy)phenyl 4- n-heptylbenzoate (7BB4CN), are compared. They have the same molecular core whereas the strongly polar CN group is attached to the benzene ring in 7BBCN or is separated from it by the butyloxy chain in 7BB4CN. 7BBCN has a nematic phase, whereas 7BB4CN exhibits a monotropic nematic and smectic A2 polymorphism. Large differences in the dielectric properties of the two substances were found. The analysis of the results led to the conclusion that the antiparallel dipole-dipole associations are considerably stronger in the substance with a decoupled CN group.

Cyanoacetyldiazoindol-2-one (3), the condensation product of cyanoacetohydrazide with isatin (1), could be cyclized in acidic medium via its CN group and its enolic OH to give cyanomethyloxadiazole-spiroindoline (4). The presence of the methylcyano side chain could be invested—through oximation, diazotization, or condensation with aldehydes—to form polyfunctional spiroindolines 5, 8–10. Also, a second route for preparing the title compound could be achieved through a nucleophilic attack on position 3 in the isatin derivatives, followed by subsequent ring closure to give 6 and 7. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:207–210, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10020

Langmuir films of binary mixtures of the following liquid crystal materials: 4-octyl-4′-cyanobiphenyl (8CB) or 4-pentyl-4″-cyano-p-terphenyl (5CT) with 4-(trans-4'-octylcyclohexyl)isothiocyanatobenzene (8CHBT), trans-4-octyl(4′-cyanophenyl)cyclohexane (8PCH) or 4-octyl4′-isothiocyanatobiphenyl (8BT) were investigated. Surface pressure-mean molecular area isotherms were recorded at various mixture compositions. It was found that only liquid crystal materials for which the molecules have a terminal -CN group are able to form a stable monolayer at the air-water interface. Moreover, information about the miscibility or the phase separation of the two components in the mixures was obtained by using the excess area criterion and surface phase rules.

Thermolysis of Ru{η3-C(CN)2CPhCC(CN)2}(PPh3)Cp* (2), obtained from Ru(CCPh)(PPh3)2Cp* and tetracyanoethene, has given the three complexes Ru{η1,η2(C,N)-C(CN)C(CN)CPhC(CN)(CN)}(PPh3)Cp* (3), {Ru(PPh3)Cp*}{μ-N:η3-NCC(CN)CPhCC(CN)2}{μ-η1:N-C(CN)C(CN)CPhC(CN)2}{RuCp*} (4) and {Ru[η3-C(CN)2CPhCC(CN)2]Cp*}3 (5). All four complexes have been characterised by single-crystal X-ray structure determinations and contain isomeric forms of the C4(CN)4Ph ligand. Unusual features of the molecular structures are (i) the presence of a side-on (η2) CN group in 3; (ii) formation of a second isomer of the polycyanocarbon ligand by CN migration to an adjacent carbon, in 3 and 4; (iii) the use of one or more CN groups to bridge ruthenium centres in 4 and 5; and (iv) the complete loss of PPh3 ligands during the formation of the trimer 5. Although there are three crystallographically distinct RuCp* groups in 5, only one Cp* resonance is found in solution NMR spectra, suggesting that oligomer formation by facile CN–Ru bond breaking and making is occurring.

Two novel Er-Cr ion-pair complexes ([Er(DMA)3(H2O)4][Cr(CN)6] and [Er(MPL)4(H2O)3][Cr(CN)6]·2H2O; DMA = dimethylacetamide, MPL = 1-methyl-2-pyrrolidinone) have been synthesized. [Er(DMA)3(H2O)4][Cr(CN)6] crystallizes in the monoclinic system (space group P c ) with a = 9.789(2), b = 11.263(2), c = 13.997(3)A, β = 105.66(3)°, V = 1485.9(5)A3, Z = 2; [Er(MPL)4(H2O)3][Cr(CN)6]·2H2O crystallizes in the monoclinic system (space group P21) with a = 9.447(2), b = 13.881(3), c = 14.673(3)A, β = 101.85(3), V = 1883.1(7)A3, Z = 2. X-Ray crystal diffraction analyses reveal that the two complexes form a hydrogen bonding network structure through the CN group and H2O molecules. Variable temperature susceptibilities for the two complexes indicate that weak antiferromagnetic interactions exist between cation and anion pairs through this hydrogen bonding network.

The title inclusion compound [{NH2(CH2CH2)2NCH2CH2NH2}2H][Cu4(CN)7] was obtained as single crystals from an aqueous solution containing CuCN, KCN, andN-(2-aminoethyl)piperazine. It crystallizes in the monoclinic space groupP2/n,a = 12.3829(9),b = 8.5970(9),c = 12.6633(7) A, β = 109.984(5)°,z = 2,R = 0.035 for 2921 independent reflections. The inclusion structure is composed of the hydrogen-bonded dimeric onium guest [{NH2(CH2CH2)2NCH2CH2NH2}2H]3+ and the negatively-charged three-dimensional host [CU4(CN)7]3− in which the CN-bridged framework Cu(I) atoms are all tetrahedral. A polyacene-like one-dimensional array of hexagons cornered by Cu(I) atoms and edged by -CN- linkages is arrayed in parallel to theb axis and stacked approximately along the c axis. The Cu(I) corner shared in the one-dimensional array extends an N-coordinate CN group along the c axis to a pair of unshared Cu(I) corners for which the C end behaves as a bifurcated ligand to build up the three-dimensional host structure. The cavity is composed of two networks of the hexagons at the top and bottom and pillared by six >CN- groups and accommodates a dimeric guest ofN-(2-aminoethyl)piperazinium cations protonated at each 4-N with the cations being hydrogen-bonded to each other through the 2-NH2 groups sharing another H+.

The slightly yellow-coloured title complex, [Zn(C18H16N4O4)(H2O)]n, crystallizes with one molecule in the asymmetric unit. The structure clearly shows themer-η4O,O,N,N-binding mode of theN,N′-bis-(2-cyano-ethylpropenoyl)-1,2-diamidobenzene ligand stabilizing the Zn centre of a distorted octahedral environment. The fifth coordination site in one apical position is held by a coordinating solvent water molecule whereas the complete octahedral coordination sphere is completed by coordination of one N atom from a CN group of a neighbouring molecule, leading to the final polymeric structure consisting of zigzag staggered chains in parallel orientation along thec-axis direction. Between the coordinated water solvent molecule and the N atoms of uncoordinated cyano-groups of neighboured units, two H-bridge bonds are formed. One of these H-bridge bonds is of inter- whereas the other of intra-strand nature, leading to a two-dimensional network parallel to (110) stabilizing the supramolecular structure. Six Zn—O or Zn—N bonds are found with lengths ranging from 2.061 (1) to 2.185 (1) Å and bond angles about the Zn atom are clustered in the ranges 79.83 (4)–104.21 (4) and 167.05 (4)–170.28 (4)°.

The title compound, C24H29NO3, has a phase sequence of crystals–smectic A–nematic–isotropic liquid. The molecular length of the compound is 25.323 (9) A. Intermolecular contacts between two CN groups, between a carbonyl­oxy and a CN group, and between two carbonyl­oxy groups are observed in the crystal state.

Tris(benzo[b]thienyl)methanol (1) forms pseudo-polymorphs of crystalline host–guest compounds enclathrating MeCN in different ratios. These are characterized by the formation of discrete –OH---NC hydrogen bonds. The FTIR spectra show that the 1∶1 crystal is comprised of strong interactions, while the 2∶1 one of weak –OH---NC interactions. The 2∶1 crystal forms an unusual bifurcated hydrogen bonding to the CN group, as revealed by an X-ray crystal analysis. The 1∶1 crystal is transformed to the 2∶1 one at 80 °C by release of half of the guest molecules and reorganization of the hydrogen bonding and is further converted to the guest-free crystal of 1 at 150 °C.

The previously reported 14N NQR spectrum of the CN groups of Ba [Fe (CN) 5NO] · 3H2O (BNP) was shown to also contain lines of Na2 [Fe (CN) 5NO] · 2H2O used in the preparation of BNP. The number of NQR lines and their relative intensities in BNP confirmed that it has a Pbcm instead of a Pca21 space group at 293 K as previously assumed. The three CN sites found in BNP at room temperature are increased to five below 233 K and to eight below 131 K as a result of phase transitions. The effect on the NQR lines of the axial CN group of the disorder of some water molecules in BNP is also discussed.

Normally disfavored 5-endo-trig cyclizations proceed in N-homoallylsulfonamides bearing a CF(3), CCl(3), CO(2)Et or CN group at the C-3 position, via an intramolecular S(N)2'-type or addition reaction to construct pyrrolidine rings, even though the system allows a more favorable 5-exo-trig pathway.

Formation of the donor-acceptor complexes of group 13 metal derivatives with nitriles and isonitriles X(3)M-D (M = Al,Ga,In; X = H,Cl,CH(3); D = RCN, RNC; R = H,CH(3)) and their subsequent reactions have been theoretically studied at the B3LYP/pVDZ level of theory. Although complexation with MX(3) stabilizes the isocyanide due to the stronger M-C donor-acceptor bond, this stabilization (20 kJ mol(-1) at most) is not sufficient to make the isocyanide form more favorable. Relationships between the dissociation enthalpy DeltaH degrees (298)(diss), charge-transfer q(CT), donor-acceptor bond energy E(DA), and the shift of the vibrational stretching mode of the CN group upon coordination Deltaomega(CN) have been examined. For a given metal center, there is a good correlation between the energy of the donor-acceptor bond and the degree of a charge transfer. Prediction of the DeltaH degrees (298)(diss) on the basis of the shift of CN stretching mode is possible within limited series of cyanide complexes (for the fixed M,R); in contrast, complexes of the isocyanides exhibit very poor Deltaomega(CN) - DeltaH degrees (298)(diss) correlation. Subsequent X ligand transfer and RX elimination reactions yielding monomeric (including donor-acceptor stabilized) and variety of oligomeric cage and ring compounds with [MN]n, [MC]n, [MNC]n cores have been considered and corresponding to thermodynamic characteristics have been obtained for the first time. Monomeric aluminum isocyanides X(2)AlNC are more stable compared to Al-C bonded isomers; for gallium and indium situation is reversed, in qualitative agreement with Pearson's HSAB concept. Substitution of X by CN in MX(3) increases the dissociation enthalpy of the MX(2)CN-NH(3) complex compared to that for MX(3)-NH(3), irrespective of the substituent X. Mechanisms of the initial reaction of the X transfer have been studied for the case X = R = H. The process of hydrogen transfer from the metal to the carbon atom in H(3)M-CNH is thermodynamically favorable and is likely to be intramolecular. By contrast, intramolecular hydrogen transfer in H(3)M-NCH has been definitely ruled out. Head-to-tail dimeric species [H(3)M-(NC)H](2) are formed exothermically and exhibit low H.H distances, which can assist in hydrogen transfer, and are likely to be the starting point for H(2) elimination. Elimination of H(2), CH(4), and C(2)H(6) from X(3)M-(NC)R adducts is very favorable thermodynamically; by contrast, elimination of HCl and CH(3)Cl is highly unfavorable even if formation of oligomer species takes place. Thus, high-temperature generation of gas-phase rings and clusters has been predicted viable in the cases X = H,CH(3) and their presence in the reactor media should not be neglected. Moderate stability of [HMCH(2)NH](4) clusters (especially in the cases M = Ga, In) makes these species viable intermediates of gas-phase reactions. Their formation may be responsible for the carbon contamination in the course of metal organic chemical vapor deposition processes of group 13 binary nitrides.

In the title compound, C(10)H(10)N(4)O, the dihedral angle between the pyridine ring and the -C=O(CH(2))CN group is 24.08 (12)°. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds generate R(2) (2)(8) loops.

A novel bipolar host material mCPCN has been designed and synthesized by incorporating the electron-accepting CN group into the well-known benchmark host material mCP. Compared to mCP, the incorporation of the simple and small CN group significantly improves thermal/morphological stabilities (Tg = 97 °C and Td = 313 °C) and increases the electron affinity, while keeping electronic transition energies unaltered and maintaining a high triplet energy (ET = 3.03 eV). Characteristics of single-carrier devices containing mCPCN indicate its rather balanced hole/electron injection and transport properties. Highly efficient blue phosphorescent organic light emitting devices (PhOLEDs) with maximum external quantum, current and power efficiencies of 26.4%, 58.6 cd A−1, and 57.6 lm W−1, respectively, were achieved using mCPCN as the bipolar host material and bis[(4′,6′-difluorophenyl)pyridinato-N,C2′]iridium(III) picolinate (FIrpic; ET = 2.65 eV) as the triplet emitter. Furthermore, blue PhOLEDs adopting mCPCN exhibit impressively low efficiency roll-offs, retaining high quantum efficiencies of ∼25% at 1000 cd m−2 and ∼20% even at 8000 cd m−2. mCPCN has also been successfully used in implementing highly efficient white PhOLEDs having external quantum efficiencies in excess of 23%.

The title compound, C6H7N3, has an ethylene group connecting an imidazole ring and a –CN group. These groups are in a staggered conformation. The shortest intermolecular contact is found between the imidazole N atom and a –CH2– group of a neighboring molecule.

The asymmetric unit of the title compound, [Co(NH(3))(6)][Mn(CN)(6)], contains one Co and one Mn atom, both lying on threefold inversion axes, and one NH(3) and one CN group. The octa-hedral environments around Co(II) and Mn(II) are generated by symmetry and show very slight deviations from ideal geometry. A three-dimensional network is created by N-H⋯N hydrogen bonds.

[fac-Re(bpy)(CO)3CN] was photochemically formed from [fac-Re(bpy)(CO)3(4-CNpy)]+ with a 53% yield using 365 nm irradiation in the presence of triethanolamine (TEOA). This rearrangement proceeds via formation of solvent complexes [fac-Re(bpy)(CO)3(DMF)]+ and [fac-Re(bpy)(CO)3(TEOA)]+.

1. Alkanone cyanohydrins of general formula R(CH2)3CR'(OH)CN (R=H or alkyl, R' =alkyl) are efficiently oxidized by the system S2O82--Ag+ to 1-cyanoalkoxyl radicals, which then undergo a highly selective rearrangement, with successive migration of the H atom and CN group and oxidation to δ-ketonitriles RCH(CN)CH2CH2COR'. 2. The cyanohydrins of 2-pentanone (Ia), 2-hexanone (Ib), 2-octanone (Ic), and 2-nonanone (Id) are oxidized by the system S2O82--Ag+ ∿4-18 times faster than tert-butanol, and in their oxidative ability they fall into the sequence: (Id) > (Ic) > (Ib) > (Ia). 3. A new method was developed for the synthesis of the nitriles of 5-ketoalkanoic acids.

A correlation between lap shear bond strength and an infrared absorbance ratio of reactive groups in a commercial dicyandiamide (dicy.)-cured epoxy adhesive was explained by the presence of a hidden factor in the nitrile absorbance measurement of the dicyandiamide. The absorbance at 2210 cm−1 due to the CN of the dicy. was the denominator of the absorbance ratio in the correlation. Water present in the adhesive changed the two infrared absorptions in the 2200 cm−1 region of the spectrum resulting in a lower 2210 cm−1 absorbance than expected stoichiometrically for high (0.4%) water concentrations in the adhesive.

New arenemanganese dicarbonyl cyanides with ω-functional substituents in the side chain were prepared, and a principally new possibility for nitrogen of the CN group coordinated with manganese in arenemanganese dicarbonyl cyanides to enter into additional complex formation with an atom of a transition metal was shown.

1. The reaction of a-nitroolefins, containing the aryl or the ferrocenyl substituent at the double bend, with cyclooctatetraene dipotassium in THF gives dimers derivatives of propane-ω,ω-dinitronic acids. 2. The distribution of the spin density in the anion-radicals ofα-nitro- and α-cyano-βferrocenylethylenes is characterized as follows: the NO2 group surpasses the ferrocenyl group in the competition for the unpaired electron, and the CN group appears to be comparable with, or even weaker than, the ferrocenyl group.

The changes in chemical shift induced by isomerization for all the ring protons of the Z- and E-5,5-dimethyl-2-cyclohexenylidene acetonitriles depend only on the through-space effects of the cyano group. The configurational assignments were made taking into consideration the anisotropic and electric field effects, either separately or together. In the first case, the total effects are ΔXCNT=−14.7×10−6cm3 mol−1 and bμCNT=14.7×10−30 cm3, respectively. The second approach allows the estimation of the values ΔXCN=−4.9 × 10−6 cm3 mol−1 and bμCN=9.8 × 10−3 cm3, reflecting the combined contributions of magnetic anisotropy and electric field to the total effect.

Arylation of [AuCl(tht)](tht = tetrahydrothiophene) with [{Ag(mes)}4](mes = mesityl) gives [{Au(mes)}5]. Both the silver and gold complex can be used for the syntheses of mono- or bi-nuclear cationic, neutral, or anionic mesitylgold complexes of the form Au(mes) L [L = PPh3, PPh2Me, P(OPh)3, or ½(Ph2PCH2PPh2), [{Au(PPh3)}2(µ-mes)]CIO4, Q[Au(mes)X](Q = NEt4 or NBu4; X = C6F5 or Cl), or [N(PPh3)2][(mes)Au(CN)Au(mes)]. The structures of NEt4[Au (mes) Cl] and [N(PPh3)2][(mes)Au(CN)Au(mes)] have been determined by single-crystal X-ray methods. The complex NEt4[Au(mes)CI] crystallizes in space group P21/n with a= 8.526(1), b= 13.917(2), c= 16.457(2)A, β= 101. I 4(1)°, and Z= 4; R 0.038 for 2 656 unique observed reflections. The Au–Cl bond is long and the Au–C bond short [2.328(2) and 2.018(7)A respectively]. The complex [N(PPh3)2][(mes)Au(CN)Au(mes)] crystallizes in space group C2/c with a= 27.702(8), b= 12.318(4), c= 20.501(6)A, β= 135.61(1)°, and Z= 4; R 0.037 for 3 576 unique observed reflections. The anion and the cation both have imposed crystallographic two-fold symmetry, and the bridging CN group must therefore be disordered. The Au–C(mesityl) bond length is 2.035(11)A.

The dispacement of a —CN group inp-(tricyanovinylidene)-phenylhydrazones, induced by amines, is investigated. The rate of the reaction is dependent on the polarity of the solvent and the observed second-order rate coefficientskobs2 for the —CN displacement increase with the amine concentration. A X-ray analysis of one of the substituted compounds is also reported.

Polymeric coordination complexes of the type (ML.2H2O)n, where M(II) - Mn, Fe, Ni, Cu or Zn and L = N1 -(4-chlorophenyl)-N4-(3,5-dinitrobenzoyl)thiosemicarbazide have been synthesised and characterised by microanalytical, I. R., magnetic, D. R. S. and thermal analysis. The IR spectra indicate tetradentate ligand coordination through the enolic oxygen, thioenolic sulphur and the nitrogen atom of the CN group. The metal ion is the bridging unit between the donor sites of the ligand molecule, and it is likely that a polymeric chain grows through consecutive ligand-metal links.

The reactions of divalent Co, Ni, Cu, Pd, and Pt chlorides with NaBH4 and NaBH3CN in the presence of tertiary phosphines under inert atmosphere conditions have been examined. The nature of the product varies enormously depending upon reaction conditions, and compounds obtained include complexes involving coordinated BH4− and BH3CN− of the type MLn, MBLn, and MHBLn, (L = phosphine, B = BH4− or BH3CN−, n = 2, 3, or 4). The first univalent nickel and cobalt BH4 complexes are reported. Platinum abstracts the CN group from BH3CN− to form the species PtH(CN)L2. Infrared spectral data are reported and appear to indicate two types of bonding (M—N and M—H) between BH3CN− and metals. Some electronic reflectance spectra and magnetic properties are also reported, including those of Co(I) and Ni(I) species. Attempts are made to rationalize the data in terms of a suggested mechanism for the reduction of metal halides by NaBH4.