Molecular Structure Of Tris Research Articles

Enhancing Horizontal Ratio of Transition Dipole Moment in Homoleptic Ir Complexes for High Outcoupling Efficiency of Organic Light-Emitting Diodes.

The light-emitting dipole orientation (EDO) of a phosphorescent emitter is a key to improving the external quantum efficiency (EQE) of organic light-emitting diodes (OLEDs) without structural modification of the device. Here, four homoleptic Ir complexes as a phosphorescent emitter are systematically designed based on the molecular structure of tris(2-phenylpyridine)iridium(III) (Ir(ppy)3 ) to control the EDO. Trimethylsilane, methyl, 2-methylpropyl, and cyclopentylmethyl group substituted to pyridine ring of the ligand contribute to the improvement of the EDO from 76.5% for Ir(ppy)3 to 87.5%. A linear relationship between the EDO and the aspect ratio (geometric anisotropy factor) is founded, implying the importance of the effective area for the nonbonding force between host and dopant molecules. Also, it is investigated that the EDO enhancement mainly originates from the vertical alignment of the C3 axis of molecule in the substrate axis rather than the change in the direction of the transition dipole alignment in the molecular axis. The optical simulation reveals that the outcoupling efficiency of phosphorescent OLEDs adopting new dopants reaches 38.4%. The green OLEDs exhibiting 28.3% of EQE, 103.2cdA-1 of current efficiency, and 98.2lmW-1 of power efficiency are demonstrated, which is understood to have little electrical loss.

The unique structure of [(C4H9)4N]3[Pb(NO3)5]—one step forward in understanding transport properties in tetra-n-butylammonium-based solid electrolytes

The crystal and molecular structure of tris(tetrabutylammonium) pentanitratoplumbate(II) was determined and characterized by single-crystal and powder X-ray diffraction and IR spectroscopy. The structure is compared to other tetra-n-butylammonium-based metal complexes with inorganic ligands, showing a significant difference in space group and local surroundings. The Pb2+ cation is surrounded by five NO3− groups, forming a stable complex only in the crystal field. Part of (C4H9)4N+ cations are distorted significantly changing geometry from tetrahedra to almost flat (square) at room temperature. Discussion on possible reorientational motion of organic groups at high temperatures and its influence on ion transport processes within the crystal structure of tetra-n-butylammonium-based organic ionic plastic crystals is provided.

MOLECULAR STRUCTURE OF TRIS(ACETYLACETONATE)IRON STUDIED BY GAS-PHASE ELECTRON DIFFRACTION AND DFT CALCULATIONS

The molecular structure of tris(acetylacetonate)iron, Fe(O2C5H7)3, has been determined by synchronous gas-phase electron diffraction and mass spectrometric experiment along with quantum chemical calculations at the DFT/UB3LYP/cc-pVTZ theory level. The best agreement between theoretical and experimental intensity curves of scattered electrons was obtained for the high spin model with the symmetry D3 of molecule. The DFT calculations also resulted in high spin electronic state 6A1 of the molecule Fe(O2C5H7)3 as the ground one at the geometrical configuration of D3 symmetry.Forcitation:Petrova A.A., Tverdova N.V., Giricheva N.I. Girichev G.V. Molecular structure of tris(acetylacetonate)iron studied by gas-phase electron diffraction and DFT calculations. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 3. P. 97-99.

The molecular structure of tris(dipivaloylmethanato) thulium: Gas-phase electron diffraction and quantum chemical calculations

The molecular structure of tris-2,2,6,6-tetramethyl-heptane-3,5-dione thulium, or Tm(thd)3, has been studied by gas-phase electron diffraction monitored by mass spectrometry (GED/MS) and quantum chemical (DFT) calculations. Both the DFT(PBE0) calculations and the GED data collected at 400(8) K indicate that the molecules have D3 symmetry with a distorted antiprismatic TmO6 coordination geometry. According to GED refinements the twist angle θ, i.e. the angle of rotation of the upper O3 triangles relative to their position in regular prism is θ = 16.9(2.0)0. This value is close to both the equilibrium value obtained from the DFT calculations and to the thermal average value at the temperature of the GED experiment obtained by integration over the DFT potential energy surface. The bond distances (rh1) in the chelate ring are TmO = 2.214(5) Å, CO = 1.278(4) Å, and CC = 1.404(3) Å. The DFT calculations yielded structure parameters in close agreement with those found experimentally. As an alternative to conventional Lewis model which was realized in NBO the topological analysis of ρ(r) in the frame of Bader's quantum theory of atoms in molecule (QTAIM) was performed.

Rod-like derivatives of ferrocenylacetylene: syntheses and structure

1-Bromo-4-ferrocenylethynylbenzene was transformed into tris(4-ferrocenylethynylphenyl)boroxine and 4-ferrocenylethynylbenzoic acid, which were further converted into new rod-like ferrocenylacetylene and ferrocenylethylene derivatives. Crystal and molecular structures of tris(4-ferrocenylethynylphenyl)boroxine and (Z)-4-(2-chloro-2-ferrocenylethenyl)benzoic acid 3-(1-imidazolyl)propylamide were determined by single crystal X-ray analysis.

Preparation of amorphous water-soluble complexes of biometals with (1-hydroxyethylidene)diphosphonic acid, 2-aminoethanol, and 2-amino-2-(hydroxymethyl)propane-1,3-diol

Multifold enhancement of solubility in water of Fe(III) and Mn(II) complexes with (1-hydroxyethylidene) diphosphonic acid has been achieved by their transformation into the corresponding salts via interaction of aqueous suspensions of the poorly soluble complexes with 2-aminoethanol and 2-amino-2-(hydroxymethyl)propane-1,3-diol. Molecular structure of tris(2-hydroxyethanaminium)(1-hydroxyethylidene)-diphosphonate has been determined. Potential agricultural efficiency of the prepared iron and manganese derivatives as well as zinc and copper complexes with (1-hydroxyethylidene)diphosphonic acid as a microfertilizer has been estimated.

The molecular structure of tris(dipivaloylmethanato) lanthanides, Ln(thd)3 (Ln = La–Lu): Peculiarities and regularities

The DFT calculations for tris-2,2,6,6-tetramethyl-heptane-3,5-dionato complexes of lanthanides, Ln(thd)3 (Ln=La–Lu) were performed. The most likely geometrical structures of D3, D3h and C2v symmetry have been examined. The D3 molecular structure with distorted antiprismatic LnO6 coordination polyhedron corresponds to the minimum of a potential energy hyper-surface (PES) for all complexes being studied. The D3h and C2v configurations correspond to the first-order saddle points on the PES. The analysis of the different ways of intramolecular rearrangements has been performed. The discrepancies between theoretical and available experimental structural data of Ln(thd)3 are explained. The regularities in molecular parameters and chemical bond nature are analyzed.

The molecular structures of tris(dipivaloylmethanato)chromium and tris(dipivaloylmethanato)cobalt determined by gas electron diffraction and density functional theory calculations

The molecular structures of tris(dipivaloylmethanato)chromium and tris(dipivaloylmethanato)cobalt have been determined by quantum chemical calculations and gas electron diffraction. Both the experimental data and the theoretical results are consistent with molecular structures having D3 symmetry which is in agreement with the Kepert model. The experimental bond distances, rh1(A), and bond angles, ∠h1(°), are: Cr–O = 1.976(5), C–O = 1.287(3), C–Cr = 1.392(6), C–Ct = 1.547(3), OCrO = 90.1(0.9), CCrC = 122.3(0.9), OCCt = 114.7(0.9) and Co–O = 1.891(4), C–O = 1.269(3), C–Cr = 1.411(5), C–Ct = 1.546(3), OCoO = 95.2(0.5), CCrC = 122.5(0.9), OCCt = 115.1(0.8).

Unusual crystal and molecular structure of tris(2-hydroxyethyl)ammonium fluoride

According to the X-ray diffraction data, the crystal and molecular structure of tris(2-hydroxyethyl) ammonium fluoride (F−N+H(CH2CH2OH)3, fluoroprotatrane, substantially differs from other halo protatranes X−N+H(CH2CH2OH)3 (X = Cl, Br, and I). At X = F, to the endo-molecular LP of the nitrogen atom the HF molecule having the minimum ionic radius in a series of X− anions is bonded. The geometry of fluoroprotatrane and the cation packing in the crystal are analyzed.

Crystal and molecular structures of tris(4-N, N-Dimethylaminophenyl)antimony

X-ray diffraction shows that a tris(4-N,N-dimethylaminophenyl)antimony crystal contains four crystallographically independent molecules. With allowance for the lone pair, antimony atoms have a distorted tetrahedral coordination. The Sb-C bond lengths are 2.133(3)–2.147(3) A; the CSbC bond angles are 94.52(11)°–97.61(11)°. There are numerous intermolecular contacts C...H (2.71(22)-2.90(2) A) and N...H (2.69(2)–2.72(2) A) in the crystal.

Synthesis and molecular structures of tris(thio- and selenophenyl)stannyl complexes of cyclopentadienylcarbonylnitrosylmanganese and their reaction products with tungsten carbony

Reactions of CpMn(CO)(NO)SnCl3 (I) with sodium benzenethiolate and sodium benzenesele-nolate gave orange crystals of the complexes CpMn(CO)(NO)Sn(EPh)3, where E = S (II) or Se (III). Treatment of complex II with photochemically generated W(CO)5(THF) yielded the adduct CpMn(CO)(NO)Sn(SPh)3 · W(CO)5 (IV). A similar treatment of complex III resulted in the formation of the ditungsten complex W2(CO)4(SePh)6 (V) with transfer of all chalcogenate groups from tin to tungsten. In reactions of complexes II and III with a Pt0 complex with phosphine and acetylene, (PPh3)2Pt(Ph2C2), the chalcogenate groups are transferred from tin. Only the known Pt(II) complexes (PPh3)2Pt(EPh)2), where E= S (VI) or Se (VII). Molecular structures IV and V were characterized by X-ray diffraction. It has been found that the Mn-Sn bond in complex IV (2.5479(9) A) is nearly the same length as that found earlier for complex II (2.5328(17) A) and is substantially shorter than the sum of the covalent radii of Mn and Sn (2.78 A). The Sn-S bond is noticeably lengthened (2.5217(11) A) only for the S atom bound to tungsten (W-S, 2.5696(12) A), while the other Sn-S bonds (2.4413(12) and 2.4291(12) A) are virtually the same as in complex II (on average, 2.441 A). Complex V contains the direct W-W bond (2.8153(16) A) supplemented with four benzeneselenolate bridges in which the W-Se bonds (on average, 2.642(2) A) are longer than the two terminal W-SePh bonds (2.571(2) A). All the W-Se bonds are much shorter than the sum of the covalent radii of W and Se (2.82 A).

Synthesis of new antimony(III) and bismuth(III) aryl compounds: Crystal and molecular structure of tris(5-bromo-2-methoxyphenyl)antimony

Tris(5-bromo-2-methoxyphenyl)antimony (I) (yield, 85%) and tris(5-bromo-2-methoxyphenyl)bismuth (II) (yield, 81%) were obtained by reacting 5-bromo-2-methoxyphenyllithium with antimony(III) chloride and bismuth(III) chloride, respectively. According to X-ray diffraction data, the antimony atom in I is highly coordinated. The Sb-C bonds lengths are 2.160(1) A, 2.163(1) A, and 2.157(2) A; the Sb…O distances are 2.985(1) A, 3.051(1) A, and 3.052(1) A. The CSbC bond angles vary in the range of 92.19(6)°-94.52(6)°. Molecules of I are linked via Sb(A)…Br(B) intermolecular contacts (3.742(2) A) to form polymer chains.

Synthesis, Characterization, and Crystal Structures of Tris(2-pyridyl)phosphine Sulfide and Selenide

We report the synthesis and structural determinations of tris(2-pyridyl)phosphine sulfide and selenide, which were prepared by the reaction of 2-lithiopyridine with phosphorus trichloride at –100°C, and treatment of resulted (2-pyridyl)phosphine with elemental sulfur or selenium in hot toluene. These compounds were characterized by elemental analysis, melting point determination, mass spectroscopy, IR, 1H, and 31P NMR spectroscopies. Furthermore, the molecular structures of tris(2-pyridyl)phosphine sulfide and selenide were determined by single crystal X-ray analysis and compared with the structures of tris(2-pyridyl)phosphine and tris(2-pyridyl)phosphine oxide. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

ChemInform Abstract: Determination of the Molecular Structure of Tris(trimethylsilyl) phosphine in the Gas Phase by Electron Diffraction, Supported by Molecular Mechanics Calculations.

Abstract The molecular structure of tris(trimethylsilyl)phosphine in the gas phase has been determined by electron diffraction. Results of three refinements are reported. In the first refinement, overall C 3 symmetry and local C 3 symmetry for the SiMe 3 groups were assumed, but these groups were allowed to tilt away from one another so that their C 3 local axes no longer coincided with the PSi bonds. The major geometrical parameters were r a (PSi) 225.9 (1), r (SiC) 188.2(1) pm, ∠ SiPSi 105.1(2) and ∠ CSiC 107.9(1)°. The tilt angle was 5.9(3)°, and the SiMe 3 groups were twisted 17.2(2)° away from the staggered position, at which the overall molecular symmetry was C 3v ; the PSiC angles were therefore 106.8, 109.3 and 116.7°. In the other two refinements the restriction of C 3 symmetry within the SiMe 3 groups was removed, and the differences between SiC distances and between CSiC angles were first fixed at values calculated by molecular mechanics (MM2), and then these new restrictions were partially relaxed. Neither of these refinements fitted the experimental data quite as well as the first one.

Molecular structure of tris(cyclopropylsilyl)amine as determined by gas electron diffraction and quantum-chemical calculations

The molecular structure and conformation of tris(cyclopropylsilyl)amine (TCPSA) has been studied by means of gas-phase electron diffraction at 338 K and quantum-chemical calculations. A total of 12 relatively stable conformations of TCPSA molecule were considered. According to the experimental results and the DFT calculations the most stable conformer corresponds to a configuration (according to the Prelog–Klyne notation) of the type (−ac)(−ac)(+ac)-(−ac)(−ac)(+ac), where the first three parentheses describe the three different Si–N–Si–C torsional angles and the latter ones depict the rotation of the three cyclopropyl groups about the C ring–Si axes, respectively. The quantum-mechanical calculations were performed using various density functional (B3LYP, X3LYP and O3LYP) and perturbation MP2 methods in combination with double- and triple- ζ basis sets plus polarization and diffuse functions. The most important experimental geometrical parameters of TCPSA ( r a Å, ∠ h1 degrees) are: (Si–N) av = 1.741(3), (Si–C) av = 1.866(4), (C–C) av = 1.510(3), (C–C(Si)) av = 1.535(3), (N–Si–C) av = 115.1(18)°. For the purpose of comparison and searching for reasons leading to the planarity of the Si 3N moiety in trisilylated amines we carried out NBO analysis and optimized the geometries of numerous silylamines. Among these compounds was tris(allylsilyl)amine (TASA), which is isovalent and isoelectronic to TCPSA. Utilizing the structural results we obtained we could show that Si +⋯Si + electrostatic repulsive interaction is predominantly responsible for the planarity of the Si 3N skeleton in TCPSA and in all other trisilylamines we considered. We also found that regardless the size and partial charges of the substituents the Si–N–Si bond angle in various disilylamines amounts to 130 ± 2°.

(Me3Si)2N]3Lu: Molecular Structure and Use as Lu and Si Source for Atomic Layer Deposition of Lu Silicate Films

AbstractThe molecular structure of tris[bis(trimethylsilyl)amido]lutetium, [(Me3Si)2N]3Lu, is investigated. An agostic interaction is found between Lu and the Si atom of the silyl group. The performance of [(Me3Si)2N]3Lu as precursor to deposit Lu silicate layers by atomic layer deposition using either H2O or O3 as oxygen source is studied. Si incorporation in the films is revealed: [(Me3Si)2N]3Lu thermal decomposition and the mentioned agostic interaction contribute both to the phenomenon. [(Me3Si)2N]3Lu thermal decomposition also affects the growth rate of films deposited using H2O. The growth rate of films deposited using O3, especially at growth temperatures < 300 °C, is extremely high, probably because of the hydrogen atoms existing in [(Me3Si)2N]3Lu.

Synthesis, characterization, crystal and molecular structure of diphenyloxophosphinoethylenediamines

Bis-, tris- and tetrakis(diphenyloxophosphino)ethylenediamine compounds can be synthesized starting with ethylenediamine and chlorodiphenylphosphine. Bis(diphenylphosphino)ethylenediamine and tris(diphenylphosphino)ethylenediamine are formed as intermediates and can be oxidized to the respective phosphine oxides by oxygen dissolved in the reaction solution, while tetrakis(diphenylphosphino)ethylenediamine is less liable to oxidation and its oxidation requires a stronger oxidizing agent such as hydrogen peroxide. All the three phosphine oxides and tetrakis(diphenylphosphino)ethylenediamine can be isolated as analytically pure solid materials and are fully characterized by elemental analysis, MS and NMR spectroscopies. The crystal and molecular structure of tris(diphenylphosphino)ethylenediamine was elucidated by single crystal X-ray diffraction analysis.

Molecular Structures of Tris(dipivaloylmethanato) Complexes of the Lanthanide Metals, Ln(dpm)3, Studied by Gas Electron Diffraction and Density Functional Theory Calculations: A Comparison of the Ln−O Bond Distances and Enthalpies in Ln(dpm)3 Complexes and the Cubic Sesquioxides, Ln2O3

The molecular structures of tris(dipivaloylmethanato)neodymium(III), Nd(dpm)3, and tris(dipivaloylmethanato)ytterbium(III), Yb(dpm)3, have been determined by gas electron diffraction (GED) and structure optimizations through density functional theory (DFT) calculations. Both molecules were found to have D3 molecular symmetry. The most important structure parameters (r(a) structure) are as follows (GED/DFT): Nd-O = 2.322(5)/2.383 A, Yb-O = 2.208(5)/2.243 A, O-Nb-O = 72.1(3)/71.3 degrees , and O-Yb-O = 75.3(2)/75.8 degrees . The twist angles of the LnO6 coordination polyhedron, defined as zero for prismatic and 30 degrees for antiprismatic coordination, were theta = 19.1(3)/14.2 degrees for Nd and 20.4(2)/19.2 degrees for Yb. Structure optimizations of La(dpm)3, Gd(dpm)3 Er(dpm)3, and Lu(dpm)3 by DFT also yielded equilibrium structures of D3 symmetry with bond distances of La-O = 2.438 A, Gd-O = 2.322 A, Er-O = 2.267 A, and Lu-O = 2.232 A. The Ln-O bond distances in 12 Ln(dpm)3 complexes studied by GED decrease in a nearly linear manner with the increasing atomic number (Z) of the metal atom, as do the Ln-O bond distances in the cubic modifications of 14 sesquioxides, Ln2O3. The bond distances in the dpm complexes are, however, about 2% shorter. The mean Ln-O bond rupture enthalpies of the cubic sesquioxides calculated from thermodynamic data in the literature vary in an irregular manner with the atomic number; the La-O, Gd-O, Tb-O, and Lu-O bonds are nearly equally strong, and the remaining bonds are significantly weaker. The Ln-O bond rupture enthalpies previously reported for 11 Ln(dpm)3 complexes are on the average 13 kJ mol(-1) or about 5% smaller than in the sesquioxides, but they vary in a similar manner along the series: it is suggested that the pattern reflects variations in the absolute enthalpies of the gaseous Ln atoms.

Characterization and Crystal Structure of Tris(N′‐ethyl‐N‐piperazinyl‐carbodithioato‐s,s′)cobalt(III) Complex: Co(S2CNC4H8NC2H5)3·3H2O

AbstractThe title compound has been prepared and characterized by elemental analyses, infrared and NMR spectra, and thermal analyses. The crystal and molecular structure of tris(N′‐ethyl‐N‐piperazinly‐carbodithioato‐s,s′)cobalt(III) complex, Co(S2CNC4H8NC2H5)3·3H2O, was determined by X‐ray diffraction methods. The compound crystallizes in trigonal system, space group R‐3, with lattice parameters a=1.37700(19) nm, b=1.37700(19) nm, c=3.0090(6) nm, γ=120°, Mr=680.98, V=4.9411(14) nm3, Z=6, Dc=1.373 g/cm3, F(000)=2160, R=0.0510 and wR=0.1436. In the structure, central Co atom coordination geometry is slightly distorted octahedron with the six S atoms from the three bidentate S2CNC4H8NC2H5 ligands. The octahedron is distorted resulting from forced configuration of the four‐membered chelate ring. The six CoS bond distances are in the range of 0.22682(13)‐0.22703(14) nm. The IR and NMR spectral data are in agreement with the structural data. The thermal analytical data indicate that it decomposed completely at the temperature of 799.97 °C, leaving CoS.

Synthesis and characterization of germanium (IV) and silicon (IV) complexes derived from 9-hydroxyphenalenone: X-ray crystal and molecular structure of tris-(9-oxophenalenone)-germanium (IV) and silicon (IV) salts

Abstract The germanium (IV) and silicon (IV) complexes, tris-(9-oxophenalenone)-germanium (IV) tetrakis[3,5-bis(trifluoromethyl) phenyl] borate (7+TFPB−) and tris-(9-oxophenalenone)-silicon (IV) tetrakis[3,5-bis(trifluoromethyl) phenyl] borate (8+TFPB−), derived from 9-hydroxyphenalenone have been synthesized and characterized by elemental analyses, infrared spectra and as well as by single crystal X-ray study. The crystal structure of 7+TFPB− and 8+TFPB− shows a one-dimensional chain like structure and π-overlap between the neighbouring phenalenyl planes. The cyclic voltammograms of 7+TFPB− and 8+TFPB− show three reversible one-electron reduction steps due to the formation of the radical, anion and dianion as each phenalenyl moiety accepts an electron.