Reaction of [CpFe(CO)2I], 1 (Cp = η5-C5H5) and di(organyl)dichalcogenides, E2R2 (E = S, Se; R = Ph, CH2Ph, 2,6-(tBu)2-C6H2OH) with [LiBH4·thf] at −70 °C in toluene, followed by stirring at room temperature for 18 h yielded heteroferraboranes, [CpFe(CO)B2H4(μ-L)], 2-4 (2: L = SePh; 3: SeCH2Ph and 4: S(2,6-(tBu)2-C6H2OH). Compounds 2-4 are highly unstable and concurrent lose of boron atoms yielded organochalcogenolato-bridged complexes, [CpFe(CO)(μ-L)]2, 5-7, respectively (5: L = SePh; 6: SeCH2Ph and 7: S(2,6-(tBu)2-C6H2OH). In contrast, the reaction of 1 with di(2-furyl)ditelluride, (C4H3O)2Te2, yielded organotellurato-bridged complex, [CpFe(CO)(μ-TeC4H3O)]2, 8 and all of our attempts to isolate the boron precursor [CpFe(CO)B2H4(μ-TeC4H3O)] in pure form failed. The accuracy of these predictions in each case is established by IR, 1H, 11B, 13C, 77Se, 125Te NMR and mass spectrometry and complex 8 is further structurally confirmed by X-ray crystallography. 相似文献
The syntheses of several ethynyl-gold(I)phosphine substituted tolans (1,2-diaryl acetylenes) of general form [Au(CCC6H4CCC6H4X)(PPh3)] are described [X = Me (2a), OMe (2b), CO2Me (2c), NO2 (2d), CN (2e)]. These complexes react readily with [Ru3(CO)10(μ-dppm)] to give the heterometallic clusters [Ru3(μ-AuPPh3)(μ-η1,η2-C2C6H4CCC6H4X)(CO)7(μ-dppm)] (3a-e). The crystallographically determined molecular structures of 2b, 2d, 2e and 3a-e are reported here, that of 2a having been described on a previous occasion. Structural, spectroscopic and electrochemical studies were conducted and have revealed little electronic interaction between the remote substituent and the organometallic end-caps. 相似文献
Cyclopentadienyltricarbonyl tungsten selenocarboxylate complexes CpW(CO)3SeCOR (1) (R = C6H5 (a), 3,5-C6H3(NO2)2 (b), 3-C6H4NO2 (c), 4-C6H4NO2 (d), CH3 (e)) and cyclopentadienyltricarbonyl tungsten selenosulfonate complexes CpW(CO)3SeSO2R (2) (R = C6H5 (a), 4-C6H4CH3 (b), 4-C6H4OCH3 (c), 4-C6H4Cl (d), CH3 (e)) have been prepared from the tungsten anion [CpW(CO)3Se]− and acid- or sulfonyl chlorides respectively. The new complexes (1 and 2) have been characterized by IR, 1H NMR spectroscopies as well as elemental analysis. The crystal structure of CpW(CO)3SeCO-3-C6H4NO2 (1c) was determined. 相似文献
The potentials of a series of one-electron oxidation and reduction reactions have been determined for manganese group half-sandwich complexes of the tricarbadecaboranyl ligand PhC3B7H9 and the penta-organo fullerene ligand C60Bn2PhH2 (Bn = benzyl). The anodic processes were studied in CH2Cl2 and the cathodic processes were studied in both CH2Cl2 and THF, the supporting electrolyte being [NBu4][B(C6F5)4]. The manganese complex Mn(CO)2(PMe3)(PhC3B7H9) (1) is a member of a three-electron transfer series which includes oxidation to 1+ (0.51 V versus ferrocene) and successive reductions to 1− (−1.66 V) and 12− (−1.77 V). Both the oxidation and reduction of the closely-related complex Mn(CO)2(PPh3)(PhC3B7H9) (2) are chemically irreversible under slow-scan cyclic voltammetry conditions. The rhenium complex Re(CO)2(PPh3)(PhC3B7H9) (3) oxidizes (E1/2 = 0.82 V versus ferrocene) to a radical cation which, unlike its cyclopentadienyl analogue, shows no evidence of dimerization. Oxidation of the fullerene-based complex Re(CO)3(C60Bn2PhH2) is more facile than that of its cyclopentadienyl analogue, in contrast to previous findings in this class of metal-fullerene derivatives. An electrochemical ligand factor, EL, of 0.63 is calculated for the PhC3B7H9 ligand in manganese group half-sandwich complexes. 相似文献
Reaction of [Co(CO)3(NO)] with [2-NMe3-closo-2-CB10H10] in refluxing CH2Cl2 affords the mono- and di-cobalt complexes [1-NMe3-2-CO-2-NO-closo-2,1-CoCB10H10] (3) and [2,7-{Co(CO)(NO)}-7-(μ-H)-1-NMe3-2-CO-2-NO-closo-2,1-CoCB10H9] (4), respectively, of which 4 contains formally both Co(I) and Co(-I) centers. Compound 4 reacts with CO to give 3, or with donor ligands L in the presence of Me3NO to afford simple substituted species, [1-NMe3-2-L-2-NO-closo-2,1-CoCB10H10] (compounds 5; L = PEt3, PPh3, CNBut). 相似文献
Calculations performed at the ab initio level using the recently reported planar concentric π-aromatic B18H62+(1) [Chen Q et al. (2011) Phys Chem Chem Phys 13:20620] as a building block suggest the possible existence of a new class of B3nHm polycyclic aromatic hydroboron (PAHB) clusters—B30H8(2), B39H92?(3), B42H10(4/5), B48H10(6), and B72H12(7)—which appear to be the inorganic analogs of the corresponding CnHm polycyclic aromatic hydrocarbon (PAHC) molecules naphthalene C10H8, phenalenyl anion C13H9?, phenanthrene/anthracene C14H10, pyrene C16H10, and coronene C24H12, respectively, in a universal atomic ratio of B:C?=?3:1. Detailed canonical molecular orbital (CMO), adaptive natural density partitioning (AdNDP), and electron localization function (ELF) analyses indicate that, as they are hydrogenated fragments of a boron snub sheet [Zope RR, Baruah T (2010) Chem Phys Lett 501:193], these PAHB clusters are aromatic in nature, and exhibit the formation of islands of both σ- and π-aromaticity. The predicted ionization potentials of PAHB neutrals and electron detachment energies of small PAHB monoanions should permit them to be characterized experimentally in the future. The results obtained in this work expand the domain of planar boron-based clusters to a region well beyond B20, and experimental syntheses of these snub B3nHm clusters through partial hydrogenation of the corresponding bare B3n may open up a new area of boron chemistry parallel to that of PAHCs in carbon chemistry.
Figure
Ab initio calculations predict the existence of polycyclic aromatic hydroboron clusters as fragments of a boron snub sheet; these clusters are analogs of polycyclic aromatic hydrocarbons 相似文献
A previous study of energy-independent in vitro Ca2+ uptake by rat intestinal epithelial membrane vesicles demonstrated that uptake by Golgi membrane vesicles was greater than that by microvillus or lateral-basal membrane vesicles, was markedly decreased in vitamin D-deficient rats, and responded specifically to 1,25-(OH)2D3 repletion (R. A. Freedman, M. M. Weiser, and K. J. Isselbacher, 1977, Proc. Nat. Acad. Sci. USA74, 3612–3616; J. A. MacLaughlin, M. M. Weiser, and R. A. Freedman, 1980, Gastroenterology78, 325–332). In the present study, properties of Ca2+ uptake and release by intestinal Golgi membrane vesicles have been investigated. The initial rate of uptake was found to be saturable, suggesting carrier-mediated uptake. Uptake was markedly inhibited by Mg2+ and Sr2+, but not by Na+ or K+. Lowering the external [H+] or raising the internal [H+] resulted in enhancement of the initial rate of uptake; the intial rate was found to correlate with the internal-to-external [H+] gradient. The initial rate of uptake could be enhanced by preloading the vesicles with MgCl2 or SrCl2 but not CaCl2, NaCl, or KCl. Vesicles preloaded with K2SO4 failed to show enhanced uptake in the presence of valinomycin, suggesting that enhancement in uptake by vesicles preloaded with MgCl2 was not due to transmembrane potentials. The internal volume of the Golgi membrane vesicles was determined and found to be 9 μl/mg protein; this volume could accomodate less than 1% of the Ca2+ uptake maintained at equilibrium. Therefore, the remainder of the Ca2+ taken up was presumably bound to the Golgi membranes. A dissociation constant of 3.8 × 10?6m was found for this binding. The bound Ca2+ could be rapidly released by external Mg2+ or Sr2+, but not Ca2+, Na+, or K+. Release of bound Ca2+ could also be induced by raising the [H+] of the external medium. Failure of external Ca2+ to release bound Ca2+ suggested that the release induced by external Mg2+, Sr2+, or H+ was not due to competitive displacement of Ca2+ from its binding sites. These results indicated that Ca2+ uptake by intestinal Golgi membrane vesicles consists of carrier-mediated transport followed by binding of Ca2+ to the vesicle. The effects of H+, Mg2+, and Sr2+ on Ca2+ uptake and release suggest the existence of cation countertransport in the Golgi membrane vesicles. 相似文献
Aryloxide rhodium(I) complexes Rh(OAr)(PPh3)3 (1a: Ar=C6Cl5, 1b: Ar=C6F5, 1c: Ar=C6H4-NO2-4) react with CO in toluene solutions to produce Vaska-type complexes trans-Rh(OAr)(CO)(PPh3)2 (2a: Ar=C6Cl5, 2b: Ar=C6F5, 2c: Ar=C6H4-NO2-4). Carbonylation of a similar complex with PMe3 ligands, Rh(OC6H4-NO2-4)(PMe3)3 (3c), also forms trans-Rh(OC6H4-NO2-4)(CO)(PMe3)2 (4c). Molecular structures of the complexes are determined by X-ray crystallography and NMR spectroscopy. Complex 1a reacts with CO in the absence of solvent to produce a mixture of 2a and complex A, the latter of which shows the IR and 13C{1H} signals due to the carbonyl ligand at different positions from those of 2a. Addition of Et2O to the above mixture turns it into analytically pure 2a. Carbonylation of 1b and 1c under the solvent-free conditions produces complexes B and C as the respective products of the solid-gas reaction. Recrystallization of B and C turns them into 2b and 2c, respectively. Complex 3c also reacts with CO in the solid state to form a mixture of 4c and complex D, although the latter complex is converted slowly into 4c even in the solid state. 相似文献
Reaction of PPN[W(CO)3(R2PC2H4PR2)(SH)] (PPN=Ph3PNPPh3; R=Me, 1; R=Ph, 2) with aromatic aldehydes in the presence of trifluoroacetic acid gave tungsten complexes of thiobenzaldehydes mer-[W(CO)3(R2PC2H4PR2)(η2-SCHR′)] (R=Me, 3a-3f; R=Ph, 4a-4e) in high yields. Analogous complexes of aliphatic thioaldehydes mer-[W(CO)3(Me2PC2H4PMe2)(η2-SCHR′)] (3g-3l) could only be obtained from the highly electron-rich thiolate complex 1. The structure of 3i (R′=i-Bu) was determined by X-ray crystallography. In solution the complexes 3 and 4 are in equilibrium with small quantities of their isomers fac-[W(CO)3(R2PC2H4PR2)(η2-SCHR′)]. Reaction of complexes 3 with dimethylsulfate followed by salt metathesis with NH4PF6 gave the alkylation products mer-[W(CO)3(Me2PC2H4PMe2)(η2-MeSCHR′)]PF6 (5a-5l) as mixtures of E and Z isomers. The methylated thioformaldehyde complex mer-[W(CO)3(Me2PC2H4PMe2)(η2-MeSCH2)]PF6 (5m) was prepared similarly. Nucleophilic addition of hydride (from LiAlH4) to 5 initially gave thioether complexes mer-[W(CO)3(Me2PC2H4PMe2)(MeSCH2R′)] (mer-6) which rapidly isomerized to fac-[W(CO)3(Me2PC2H4PMe2)(MeSCH2R′)] (fac-6). 相似文献
The dinuclear bis(6-X-pyridin-2-olato) ruthenium complexes [Ru2(μ-XpyO)2(CO)4(PPh3)2] (X = Cl (4B) and Br (5B)), [Ru2(μ-XpyO)2(CO)4(CH3CN)2] (X = Cl (6B), Br (7B) and F (8B)) and [Ru2(μ-ClpyO)2(CO)4(PhCN)2] (9B) were prepared from the corresponding tetranuclear coordination dimers [Ru2(μ-XpyO)2(CO)4]2 (1: X = Cl; 2: X = Br) and [Ru2(μ-FpyO)2(CO)6]2 (3) by treatment with an excess of triphenylphosphane, acetonitrile and benzonitrile, respectively. In the solid state, complexes 4B-9B all have a head-to-tail arrangement of the two pyridonate ligands, as evidenced by X-ray crystal structure analyses of 4B, 6B and 9B, in contrast to the head-to-head arrangement in the precursors 1-3. A temperature- and solvent-dependent equilibrium between the yellow head-to-tail complexes and the red head-to-head complexes 4A-7A and 9A, bearing an axial ligand only at the O,O-substituted ruthenium atom, exists in solution and was studied by NMR spectroscopy. Full 1H and 13C NMR assignments were made in each case. Treatment of 1 and 2 with the N-heterocyclic carbene (NHC) 1-butyl-3-methylimidazolin-2-ylidene provided the complexes [Ru2(μ-XpyO)2(CO)4(NHC)], X = Cl (11A) or Br (12A). An XRD analysis revealed the head-to-head arrangement of the pyridonate ligands and axial coordination of the carbene ligand at the O,O-substituted ruthenium atom. The conversion of 11A and 12A into the corresponding head-to-tail complexes was not possible. 相似文献
The reactions of 2-amino-anthracene with [Os3(CO)10(CH3CN)2] have been studied and the products structurally characterized by spectroscopic, X-ray diffraction, photophysical and electrochemical techniques. At room temperature in CH2Cl2 two major, isomeric products are obtained [Os3(CO)10(μ-η2-(N-C(1))-NH2C14H8)(μ-H)] (1, 14%) and [Os3(CO)10(μ-η2-(N-C(3))-NHC14H9)(μ-H)] (2, 35%) along with a trace amount of the dihydrido complex [Os3(CO)9(μ-η2-(N-C(3))-NHC14H8)(μ-H)2] (3). In refluxing tetrahydrofuran only complexes 2 and 3 are obtained in 24% and 28%, respectively. A separate experiment shows that complex 1 slowly converts to 2 and that the rearrangement is catalyzed by adventitious water and involves proton transfer to the anthracene ring. Complex 1 is stereochemically non-rigid; exhibiting edge to edge hydride migration while 2 is stereochemically rigid. Complex 3 is also stereochemically non-rigid showing a site exchange process of the magnetically nonequivalent hydrides typical for trinuclear dihydrides. Interestingly, 2 decarbonylates cleanly to the electronically unsaturated 46e− cluster [Os3(CO)9(μ3-η2-(N-C(3))-NHC10H9)(μ-H)] (4, 68%) in refluxing cyclohexane, while photolysis of 2 in CH2Cl2 yields only a small amount of 3 along with considerable decomposition. The mechanism of the conversion of 1 to 2 and the dependence of the product distribution on solvent are discussed. All four compounds are luminescent with compounds 1-3 showing emissions that can be assigned to radiative decay associated with the anthracene ligand. Complexes 1-3 all show irreversible 1e− reductions in the range of −1.85-2.14 V while 4 shows a nicely reversible 1e− wave at −1.16 V and a quasi-reversible second 1e− wave at −1.62 V. Irreversible oxidations are observed in the range from +0.35 to +0.49 V. The relationship between the cluster ligand configurations and the observed electrochemical and photochemical behavior is discussed and compared with that of the free ligand. 相似文献
Reaction of [CuIIL⊂(H2O)] (H2L = N,N′-ethylenebis(3-ethoxysalicylaldimine)) with nickel(II) perchlorate in 1:1 ratio in acetone produces the trinuclear compound [(CuIIL)2NiII(H2O)2](ClO4)2 (1). On the other hand, on changing the solvent from acetone to methanol, reaction of the same reactants in same ratio produces the pentametallic compound [(CuIIL)2NiII(H2O)2](ClO4)2·2[CuIIL⊂(H2O)]·2MeOH (2A), which loses solvated methanol molecules immediately after its isolation to form [(CuIIL)2NiII(H2O)2](ClO4)2·2[CuIIL⊂(H2O)] (2B). Clearly, formation of 1 versus 2A and 2B is solvent dependent. Crystal structures of 1 and 2A have been determined. Interestingly, compound 2A is a [3 × 1 + 1 × 2] cocrystal. The cryomagnetic profiles of 1 and 2B indicate that the two pairs of copper(II)···nickel(II) ions in the trinuclear cores in both the complexes are coupled by almost identical moderate antiferromagnetic interaction (J = −22.8 cm−1 for 1 and −26.0 cm−1 for 2B). 相似文献
The reaction between [7,8-Ph2-7,8-nido-C2B9H9]2− and [(η-C7H7)Mo(MeCN)3]+ affords five products. Four have been isolated and shown to be structural isomers of (η-C7H7)MoPh2C2B9H9. Compound 1 has a pseudocloso structure. In solution it gives way to the non-icosahedral compound 2 which in turn rearranges into the “1,2 → 1,7” C-atom isomerised compound 5 having a 2,1,8-MoC2B9 structure. A further “1,2 → 1,7” C-atom isomerised species, compound 4, is also isolated but has a 1,2,4-MoC2B9 architecture. Compound 4 forms via an intermediate 3, which is too unstable to characterise. Structurally the sequence of compounds 1, 2 and 5 maps well onto the sequential diamond-square-diamond isomerisation mechanism of 1,2-closo-C2B10H12 into 1,7-closo-C2B10H12 proposed by Wales. An alternative pathway from the notional first product of the metallation, 1,2-Ph2-3-(η-C7H7)-3,1,2-closo-MoC2B9H9, is required to rationalise the intermediate compound 3 and, from it, compound 4. 相似文献
The reaction of FcCOCl (Fc = (C5H5)Fe(C5H4)) with benzimidazole or imidazole in 1:1 ratio gives the ferrocenyl derivatives FcCO(benzim) (L1) or FcCO(im) (L2), respectively. Two molecules of L1 or L2 can replace two nitrile ligands in [Mo(η3-C3H5)(CO)2(CH3CN)2Br] or [Mo(η3- C5H5O)(CO)2(CH3CN)2Br] leading to the new trinuclear complexes [Mo(η3-C3H5)(CO)2(L)2Br] (C1 for L = L1; C3 for L = L2) and [Mo(η3-C5H5O)(CO)2(L)2Br] (C2 for L = L1; C4 for L = L2) with L1 and L2 acting as N-monodentade ligands. L1, L2 and C2 were characterized by X-ray diffraction studies. [Mo(η3-C5H5O)(CO)2(L1)2Br] was shown to be a trinuclear species, with the two L1 molecules occupying one equatorial and one axial position in the coordination sphere of Mo(II). Cyclic voltammetric studies were performed for the two ligands L1 and L2, as well as for their molybdenum complexes, and kinetic and thermodynamic data for the corresponding redox processes obtained. In agreement with the nature of the frontier orbitals obtained from DFT calculations, L1 and L2 exhibit one oxidation process at the Fe(II) center, while C1, C3, and C4 display another oxidation wave at lower potentials, associated with the oxidation of Mo(II). 相似文献
Heating a benzene solution of the isomerized product of spiro[4.4]nona-1,3-diene(dicarbonyl)[ethoxy(aryl)carbene]iron phosphine adduct [(η3-C9H12)Fe{C(OC2H5)(C6H4CH3-o)}(CO)2PPh3] (1) in a sealed quartz tube at 85-90 °C for 72 h gave the ring-opened η4 olefin-coordinated dicarbonyliron phosphine complex [Fe{η4-C5H7CHCHCH2CHC(OC2H5)C6H4CH3-o}(CO)2PPh3] (3) and cyclobutane derivative [C24H22O7] (4). The thermal decomposition of analogous isomerized product [(η3-C9H12)Fe{C(OC2H5)(C6H4CH3-p)}-(CO)2PPh3] (2) afforded the corresponding η4 olefin-coordinated dicarbonyliron phosphine complex [Fe{η4-C5H7CHCHCH2CHC(OC2H5)C6H4CH3-p}(CO)2PPh3] (6) and compound 4. The structures of products 3 and 4 have been established by X-ray diffraction studies. 相似文献
Two rhenium(I) tricarbonyl complexes with the tridentate monoanionic NSO ligands, 4-(benzimidazol-2-yl)-3-thiabutanoic acid (complex 3) and [1-(11-carboxyundecanyl)-4-(benzimidazol-2-yl)]-3-thiabutanoic acid (complex 4) were synthesized and characterized by spectroscopic methods and elemental analysis. X-ray crystallographic analysis of complex 3 revealed a distorted octahedral geometry around rhenium defined by the three facially bound CO groups and the NSO donor atom set of the tridentate ligand. The analogous technetium-99m complexes (complexes 5 and 6) were also prepared quantitatively by reaction of the NSO ligands with the fac-[99mTc(H2O)3(CO)3]+ synthon and their identity was established by chromatographic comparison to their rhenium congeners. Biodistribution in mice of complex 6 bearing the fatty acid chain showed significant heart uptake (6.26 ± 0.79% ID/g p.i.) at 1 min accompanied, however, with a heart:blood ratio below 1. 相似文献
Reaction between Os(SnI3)(κ2-S2CNMe2)(CO)(PPh3)2 and NaBH4 produces the unusual, air-stable, trihydridostannyl complex, Os(SnH3)(κ2-S2CNMe2)(CO)(PPh3)2 (1), which has been fully characterised including by X-ray crystal structure determination.Similarly, reaction between Os(SnI2Me)(κ2-S2CNMe2)(CO)(PPh3)2 or Os(SnClMe2)(κ2-S2CNMe2)(CO)(PPh3)2 and NaBH4 produces the dihydridostannyl complex, Os(SnH2Me)(κ2-S2CNMe2)(CO)(PPh3)2 (4) or the monohydridostannyl complex, Os(SnHMe2)(κ2-S2CNMe2)(CO)(PPh3)2 (6), respectively.The SnH bonds in these complexes are reactive towards acids and in selected reactions complexes 1 and 4 with aqueous HF give Os(SnF3)(κ2-S2CNMe2)(CO)(PPh3)2 (3) and Os(SnF2Me)(κ2-S2CNMe2)(CO)(PPh3)2 (5), respectively, and complex 6 with aqueous HCl gives Os(SnClMe2)(κ2-S2CNMe2)(CO)(PPh3)2.The trihydridostannyl complex 1 reacts with chloroform to form the trichlorostannyl complex, Os(SnCl3)(κ2- S2CNMe2)(CO)(PPh3)2 (2). The crystal structures of 1-3, 5, and 6 have been determined. 相似文献
Halide abstraction from the 18 electron Ru(II) complex RuCl(CO)2[2,6-(CH2PtBu2)2C6H3] (2) with AgPF6 results in the exclusive formation of the cationic complex {Ru(CO)2[2,6-(CH2PtBu2)2C6H3]}+PF6− (3). The molecular structures of 2 and 3 were determined by complete single-crystal diffraction studies. X-ray crystallographic analysis of 3 reveals that the “open” coordination site is occupied by an agostic interaction between the metal center and an sp3 C-H bond of a tert-butyl substituent. DFT gas phase calculations (B97-1/SDD) show the necessity of two sterically demanding tert-butyl substituents on one P donor atom for the agostic interaction to occur. The reaction of 3 with H2 results in the quantitative conversion to {Ru(H)(CO)2[2,6-(CH2PtBu2)2C6H4]}+PF6− (4) where the aromatic Cipso-H bond is η2-coordinated to the metal center. Treatment of the agostic complex 4 with Et3N results in the formation of the neutral complex Ru(H)(CO)2[2,6-(CH2PtBu2)2C6H3] (5). The mechanistic details of 3 + H2 → 4 were investigated by DFT calculations at the B97-1/SDB-cc-pVDZ//B97-1/SDD level of theory. 相似文献
The character of the bridged hydrogen atom (Hb) of B2H6 has become a hot issue in recent years. In this work, the complexes B2H6?·?·?·?NH3, B2H2X4?·?·?·?nNH3 (n?=?1, 2) and 2HF?·?·?·?B2H2X4?·?·?·?2NH3 (X?=?Cl, Br, I) were constructed and studied based on the M06-2X calculations to investigate how to enhance the Hb?·?·?·?N hydrogen-bonded interaction. When the terminal hydrogen atoms (Ht) of B2H6 were replaced by X (X?=?Cl, Br, I) atoms, the Hb?·?·?·?N hydrogen bond were strengthened. According to the electrostatic potentials in B2H2X4, two HF molecules were added to the interspace of the B-H-B-H four-membered ring of the B2H2X4?·?·?·?2NH3 complexes, and H?·?·?·?X hydrogen bond formed, resulting in further enhancing effect of Hb?·?·?·?N hydrogen bond. As a result, the positive cooperative effect of Hb?·?·?·?N hydrogen bond and H?·?·?·?X hydrogen bond do enhance the interactions of each other. The two measures not only enhance the strength of Hb?·?·?·?N hydrogen bond, but also achieve the goal to make the Hb?·?·?·?N hydrogen bond perpendicular to B?·?·?·?B direction.
Syntheses of three new N-arylanilido-arylimine bidentate Schiff base type ligand precursors, ortho-C6H4[NH(2,6-iPr2C6H3)](CHNAr1) [Ar1 = p-FC6H4 (2a); C6H5 (2b); p-OMeC6H4 (2c)], and their four-coordinated boron complexes, ortho-C6H4[N(2,6-iPr2C6H3)](CHNAr1)BF2 [Ar1 = p-FC6H4 (3a); C6H5 (3b); p-OMeC6H4 (3c)] are described. The boron complexes 3a-3c were synthesized from the reaction of BF3(OEt2) with the lithium salt of their corresponding ligand. All complexes were characterized by 1H and 13C NMR spectroscopy and molecular structures of complexes 3a and 3c were determined by X-ray crystallography. The photophysical properties of complexes 3a-3c were briefly examined. All three complexes display bright green fluorescence in solution and in the solid state. Electroluminescent devices with complex 3c as the emitter were fabricated. These devices were found to give green emission with maximum current efficiency of 2.92 cd/A and maximum luminance of 670 cd/m2. 相似文献