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1.
Based on the “arm-first” strategy, ring-opening polymerization (ROP) and one-pot azide–alkyne click reaction, well-defined star-shaped polymers with different architectures have been successfully synthesized, including the star homopolymers four-arm star-shaped polycaprolactone (4sPCL) and four-arm star-shaped poly(l-lactic acid) (4sPLLA), star-block copolymer 4sPCL-b-PLLA and miktoarm star-shaped copolymer PCL2PLLA2. The star homopolymers 4sPCL and 4sPLLA were synthesized by a click reaction of an azide small molecule initiator and HC C-PCL or HC C-PLLA. The star-block copolymer 4sPCL-b-PLLA was synthesized by a click reaction of an azide small molecule initiator and the block copolymer HC C-PCL-b-PLLA. The miktoarm star polymer PCL2PLLA2 was synthesized by a one-pot azide–alkyne click reaction of simultaneous addition of equal proportions of HC C-PCL and HC C-PLLA. The structures of these star-shaped polymers have been confirmed by NMR, FT-IR and GPC. Furthermore, the melting and crystallization behaviors investigated using DSC and WXRD also confirm the formation of star-shaped polymers with different architectures.Star, star-block, and miktoarm star biodegradable polymers were synthesized by an “arm-first” strategy, ring-opening polymerization and one-pot azide-alkyne click reaction. 相似文献
2.
For over 100 years, known bent C C compounds have been limited to those with organic (I) and all-carbon (II) scaffoldings. Here, we computationally report a novel type (III) of bent C C compound, i.e., C2Al4F6-01, which is the energetically global minimum isomer and bears an inorganic–metallic scaffolding and unexpected click reactivity.We report a novel C2Al4F6-01 with metal–inorganic Al4F6-scaffolding, which differs from hitherto known bent-C C types, which all involve carbon-based scaffoldings. 相似文献
3.
Manuel P. Hgerl Li Min Serena Goh Edy Abou-Hamad Samir Barman Oliver Dachwald Farhan Ahmad Pasha Jeremie Pelletier Klaus Khler Valerio D'Elia Luigi Cavallo Jean-Marie Basset 《RSC advances》2018,8(37):20801
Vanadium oxytriisopropoxide (VO(OiPr)3), 1, was grafted on highly dehydroxylated silica (SiO2-700: aerosil silica treated at 700 °C under high vacuum) to generate compound 2 following the concepts and methodology of surface organometallic chemistry (SOMC). The resulting compound was analyzed by elemental analysis, FT-IR, 1H, 13C and 51V solid state (SS) NMR, Raman and EPR spectroscopies. The grafting reaction of 1 to generate 2 was found to lead to the formation of a monopodal surface complex [( Si–O–)V(O)(OiPr)2], 2m, as well as bipodal [( Si–O–)2V(O)(OiPr)], 2b, formed along with ( Si–O–iPr) moieties as an effect of the classical rearrangement of 2m with strained siloxane bridges. Upon controlled thermal treatment at 200 °C under high vacuum, 2m and 2b were found to mainly rearrange to tetrahedral VO4 moieties [( Si–O–)3V(O)] (3) with formation of propylene whereas the ( Si–O–iPr) groups were preserved. The mechanism of the thermal rearrangement of the isopropoxide groups was investigated by a DFT approach revealing the occurrence of a concerted γ-H-transfer and olefin elimination mechanism.VO(OiPr)3 was grafted on highly dehydroxylated silica by a surface organometallic chemistry approach and its thermal evolution was analyzed with support of DFT calculations. 相似文献
4.
Reactions of 2-benzoylpyridine or 2-benzylpyridine with [Cp*MCl2]2 (M = Ir, Rh) have been carried out in the presence of NaOAc in refluxing methanol, which form the corresponding six-membered cyclometalated products (1–3) except for the reaction of 2-benzylpyridine with [Cp*RhCl2]2. Insertion reactions of two six-membered cyclometalated pyridine iridium complexes (1 and 2) with terminal or internal aromatic alkynes were studied. Terminal alkynes p-XC6H4C CH (X = H, MeO, and F) with 1 give the corresponding five- and seven-membered doubly cycloiridated complexes 4a–c, internal alkynes p-XC6H4C CC6H4X-p (X = H, MeO, and Br) form the similar five- and seven-membered doubly cycloiridated complexes (5a,b) and/or di-insertion products (6a,c), whereas the acyl alkyne PhC CCOPh affords the novel spiro-metalated complex 7. For complex 2, internal alkynes p-XC6H4C CC6H4X-p (X = H, MeO, and Br) form similar five- and seven-membered doubly cycloiridated complexes (8a–c). However, in the case of PhC CCOPh, the reaction gives the novel four-membered cyclometalated complex 9. These results suggest that the products formed by alkyne insertion reactions of the six-membered cycloiridated pyridine complexes are very diverse. Plausible pathways for the formation of these novel insertion products were proposed. Molecular structures of seven cyclometalated complexes were determined by X-ray diffraction.Insertion reactions of aromatic alkynes into the Ir–C bond of six-membered cycloiridated complexes formed various novel products via different insertion modes. 相似文献
5.
Compared with rare earth elements and heavy metal elements, rare-earth-element-free fluorescent films can greatly reduce environmental hazards. In this study, we use a solution method to produce the fluorescent films. The film thickness is 10 μm, which can maintain fluorescent light intensity in an environment with an average humidity of 55.1 (RH%) after encapsulation. We also find that the type of solvent affects the resonance position of the C N functional group in DCJTB at a wavenumber of 2196 (cm−1), measured with Fourier transform infrared spectroscopy. The functional group is affected by the polar effect with its displacement decreasing with the quantum yield. Finally, we successfully made a fluorescent solution with a resonance displacement of only 12.8 (cm−1) for the C N functional group with the quantum yield being as high as 81.3% and a fluorescent film with a quantum yield as high as 84.8%.The fluorescent solution with a resonance displacement of only 12.8 (cm−1) for the C N functional group gives this film a quantum yield as high as 84.8%. 相似文献
6.
Mingrui Wei Tingting Zhang Xianfeng Chen Fuwu Yan Guanlun Guo Dongju Zhang 《RSC advances》2018,8(24):13226
The formation of polycyclic aromatic hydrocarbons (PAHs) on the C11H11 potential energy surface involved in the reactions of a phenyl radical (C6H5) with cis-3-penten-1-yne (cis-C1H C2–C3H C4H–C5H3, referred to as C5H6) and its three radicals (CH C–Ċ CH–CH3, CH C–CH Ċ–CH3, and cis-CH C–CH CH–ĊH2, referred to as the C3-, C4-, and C5-radicals with the same chemical components, C5H5) assisted by H atoms is investigated by performing combined density functional theory (DFT) and ab initio calculations. Five potential pathways for the formation of PAHs have been explored in detail: Pathways I–II correspond to the reaction of C6H5 with C5H6 at the C1 and C2 position, and Pathways III–V involve the reaction of C6H5 with the C3-, C4-, and C5-radicals with the assistance of H atoms. The initial association of C6H5 with C5H6 or C5H5 is found to be highly exothermic with only minor barriers (1.4–7.1 kcal mol−1), which provides a large driving force for the formation of PAHs. The hydrogen atom is beneficial for the ring enlargement and ring formation processes. The present calculations predict 9 potential PAHs, six (CS6, CS10, CS13, CS26, CS28 and CS29) of which are indicated to be energetically more favorable along Pathways I, III, IV and V at low temperature. The calculated barriers for the formation of these PAHs are around 19.2–38.0 kcal mol−1. All PAHs products could be formed at flame temperature, for the medium barriers are easily overcome in various flame conditions. The theoretical results supplement the PAH formation pathway and provide help to understand PAH growth mechanism.The formation of PAHs within 4-, 5-, 6- and 7-membered rings on the C6H5 + C5H6 potential energy surface. 相似文献
7.
A trifluoromethanesulfonate (OTf) and tert-butylacetylene (tBuC C−) co-protected silver nanocluster (NC), Ag43(tBuC C)24(CF3SO3)8 (Ag43), was synthesized and characterized. Single crystal X-ray diffraction analysis revealed its total structure. 43 Ag atoms are arranged into a three-concentric-shell Ag@Ag12@Ag30 structure. Both OTf and tBuC C− ligands bonded with Ag atoms in a μ3 mode. The application of Ag43 as a catalyst for the reaction of silane with alcohol or H2O indicated that the surface ligands had a profound passivation effect, which significantly influenced the reactivity and selectivity.A trifluoromethanesulfonate (OTf) and tert-butylacetylene (tBuC≡C−) co-protected silver nanocluster (NC), Ag43(tBuC≡C)24(CF3SO3)8 (Ag43) was synthesized and characterized. Its surface ligands have shown strong passivation effect in the reaction catalyzed by Ag43. 相似文献
8.
An original method for the one-stage synthesis of sulfur-containing silica of SBA-15 type is developed and described. Instead of tetraethylorthosilicate (TEOS) typically used as a source of silica, the inexpensive sodium metasilicate has been applied in our method. The mesoporous silica material was first functionalized with thiol groups then oxidized by concentrated nitric acid to produce sulfonic groups. The samples obtained possess developed specific surface area (Ssp = 320–675 m2 g−1) and porous structure with an effective pore diameter of 3.5–5.7 nm. The orderliness of the structure and presence of surface sulfur-containing acidic groups of various natures in the synthesized materials were determined using XRD, TEM, N2 adsorption, conductivity and potentiometric titration methods. Based on the results of the measurements of the zeta potential vs. pH and electrolyte concentration, conclusions about the electro-surface properties and aggregation stability of sample dispersion have been drawn. The obtained samples are environmentally-friendly and could be used in green chemistry.Hybrid Si(CH2)3SH–SBA-15 and Si(CH2)3SO3H–SBA-15 silicas were obtained with developed specific surface area and an effective pore diameter of 3.5–5.7 nm. 相似文献
9.
The phase assembly and microstructure of the aluminum-incorporated CaO–SiO2–H2O system, which is technologically important in autoclaved building materials, catalysis and waste management, were investigated using XRD, SEM, FTIR and NMR depending on aluminum addition, reaction temperature and curing time. The content of each phase was obtained using the MAUD program based on the Rietveld refinement. The results revealed that the formation of the tobermorite phase was promoted at Al/(Al + Si) ≤ 0.03, and subsequently retarded by higher aluminum addition, which was corroborated by the presence of more low polymerized and cross-linked (alumino)silicate chains. The phase purity decreased with increasing aluminum addition. Aluminum changed the morphology of tobermorite from plate-like to lath-like and fibrous. About a quarter of the (alumino)silicate chains in the C–S–H structure were linked though a Si–O–Al configuration, and this proportion was almost independent of aluminum addition. Furthermore, only Al[4] substituted for silicon in the aluminum incorporated C–S–H, while Al[6] just exited in the hydrogarnet phase. This work is beneficial for understanding the implication on micro-properties of by-products or admixtures containing aluminum in concrete.The phase assembly and microstructure of the aluminum-incorporated CaO–SiO2–H2O system were investigated using XRD, SEM, FTIR and NMR depending on aluminum addition, reaction temperature and curing time. 相似文献
10.
Recently, inexpensive and readily available tBuOK has seen widespread use in transition-metal-free reactions. Herein, we report the use of tBuOK for S–S, S–Se, N N and C N bond formations, which significantly extends the scope of tBuOK in chemical synthesis. Compared with traditional methods, we have realized mild and general methods for disulfide, azobenzenes imine etc. synthesis.Inexpensive and readily available tBuOK can trigger a series of bond formation reactions, including S–S, S–Se, Se–Se, and N N and C N bonds. 相似文献
11.
Md. Tuhinur R. Joy Roknuzzaman Md. Emdad Hossain Shishir Ghosh Derek A. Tocher Michael G. Richmond Shariff E. Kabir 《RSC advances》2020,10(51):30671
The reaction of the trimetallic clusters [H2Os3(CO)10] and [Ru3(CO)10L2] (L = CO, MeCN) with 2-ethynylpyridine has been investigated. Treatment of [H2Os3(CO)10] with excess 2-ethynylpyridine affords [HOs3(CO)10(μ-C5H4NCH=CH)] (1), [HOs3(CO)9(μ3-C5H4NC CH2)] (2), [HOs3(CO)9(μ3-C5H4NC CCO2)] (3), and [HOs3(CO)10(μ-CH CHC5H4N)] (4) formed through either the direct addition of the Os–H bond across the C C bond or acetylenic C–H bond activation of the 2-ethynylpyridine substrate. In contrast, the dominant pathway for the reaction between [Ru3(CO)12] and 2-ethynylpyridine is C–C bond coupling of the alkyne moiety to furnish the triruthenium clusters [Ru3(CO)7(μ-CO){μ3-C5H4NC CHC(C5H4N) CH}] (5) and [Ru3(CO)7(μ-CO){μ3-C5H4NCCHC(C5H4N)CHCHC(C5H4N)}] (6). Cluster 5 contains a metalated 2-pyridyl-substituted diene while 6 exhibits a metalated 2-pyridyl-substituted triene moiety. The functionalized pyridyl ligands in 5 and 6 derive via the formal C–C bond coupling of two and three 2-ethynylpyridine molecules, respectively, and 5 and 6 provide evidence for facile alkyne insertion at ruthenium clusters. The solid-state structures of 1–3, 5, and 6 have been determined by single-crystal X-ray diffraction analyses, and the bonding in the product clusters has been investigated by DFT. In the case of 1, the computational results reveal a rare thermodynamic preference for a terminal hydride ligand as opposed to a hydride-bridged Os–Os bond (3c,2e Os–Os–H bond).The reactivity of 2-ethynylpyridine at low-valent triosmium and triruthenium centers has been investigated. 相似文献
12.
Sai Manoj N. V. T. Gorantla Maria Francis Sudipta Roy Kartik Chandra Mondal 《RSC advances》2021,11(12):6586
Fluoro- and chloro-phosphasilynes [X–Si P (X = F, Cl)] belong to a class of illusive chemical species which are expected to have Si P multiple bonds. Theoretical investigations of the bonding and stability of the corresponding Lewis base-stabilized species (L′)PSi(X)(L) [L′ = cAACMe (cyclic alkyl(amino) carbene); L = cAACMe, NHCMe (N-heterocyclic carbene), PMe3, aAAC (acyclic alkyl(amino) carbene); X = Cl, F] have been studied using the energy decomposition analysis-natural orbitals for chemical valence (EDA-NOCV) method. The variation of the ligands (L) on the Si-atom leads to different bonding scenarios depending on their σ-donation and π-back acceptance properties. The ligands with higher lying HOMOs prefer profoundly different bonding scenarios than the ligands with lower lying HOMOs. The type of halogen (Cl or F) on the Si-atom was also found to have a significant influence on the overall bonding scenario. The reasonably higher value and endergonic nature of the dissociation energies along with the appreciable HOMO–LUMO energy gap may corroborate to the synthetic viability of the homo and heteroleptic ligand-stabilized elusive PSi(Cl/F) species in the laboratory.The bonding and stability of elusive heavier cyanogen halide analogues (L′)PSi(X)(L) have been theoretically investigated using EDA-NOCV method. Variation of ligands and halogen on Si atom had a significant effect on the stability of these species. 相似文献
13.
Yadhav A. Imrit Hanusha Bhakhoa Tetiana Sergeieva Sergi Dans Nandini Savoo Mohamed I. Elzagheid Lydia Rhyman Diego M. Andrada Ponnadurai Ramasami 《RSC advances》2020,10(47):27884
A-234, [EtO–P( O)(F)–N C(Me)–N(Et)2], is the suspected A-type nerve agent used in the Skripal attack on the 4th of March 2018. Studies related to the structure and reactivity of this compound are limited. We, therefore, aimed at understanding the underlying hydrolysis mechanism of A-234 within the DFT framework. The attack of the water molecule can occur at the phosphinate and acetoamidine reactive centres. Our theoretical findings indicate that the hydrolysis at the acetoamidine centre is thermodynamically favoured compared to the hydrolysis at the phosphinate centre. The hydrolysis at the acetoamidine moiety may proceed via two pathways, depending on the nitrogen atom participating in the hydrolysis. The main pathway consists of four distinct channels to reach the final product, with the concerted 1,3-proton shift favoured kinetically and thermodynamically in the gas phase and water as solvent. The results are in good agreement with the literature, although some differences in the reaction mechanism were observed.A theoretical study of the hydrolysis mechanism of A-234 [EtO–P( O)(F)–N C(Me)–N(Et)2]; the suspected novichok agent in the Skripal attack. 相似文献
14.
Adina Coroaba Dragos-Lucian Isac Cristina Al-Matarneh Tudor Vasiliu Sorin-Alexandru Ibanescu Radu Zonda Rodinel Ardeleanu Andrei Neamtu Daniel Timpu Alina Nicolescu Francesca Mocci Stelian S. Maier Aatto Laaksonen Marc Jean Mdard Abadie Mariana Pinteala 《RSC advances》2020,10(63):38304
A novel DPyDB-C N-18C6 compound was synthesised by linking a pyrene moiety to each phenyl group of dibenzo-18-crown-6-ether, the crown ether, through –HC N– bonds and characterized by FTIR, 1H-NMR, 13C-NMR, TGA, and DSC techniques. The quantitative 13C-NMR analysis revealed the presence of two position isomers. The electronic structure of the DPyDB-C N-18C6 molecule was characterized by UV-vis and fluorescence spectroscopies in four solvents with different polarities to observe particular behavior of isomers, as well as to demonstrate a possible non-bonding chemical association (such as ground- and excited-state associations, namely, to probe if there were forming dimers/excimers). The interpretation of the electronic structure was realized through QM calculations. The TD-CAM-B3LYP functional, at the 6-311+G(d,p) basis set, indicated the presence of predominant π → π* and mixed π → π* + n → π* transitions, in line with the UV-vis experimental data. Even though DPyDB-C N-18C6 computational studies revealed a π-extended conjugation effect with predominantly π → π* transitions, thorough fluorescence analysis was observed a weak emission, as an effect of PET and ACQ. In particular, the WAXD analysis of powder and thin films obtained from n-hexane, 1,2-dichloroethane, and ethanol indicated an amorphous organization, whereas from toluene a smectic ordering was obtained. These results were correlated with MD simulation, and it was observed that the molecular geometry of DPyDB-C N-18C6 molecule played a defining role in the pyrene stacking arrangement.Herein, we report the formation of a potential supramolecular arrangement mediated by inter- and intra-molecular interactions between di-iminopyrene-dibenzo-18-crown-6-ether molecules. 相似文献
15.
To enhance the anti-biofouling properties and adsorption capability of poly(amidoxime) (PAO), vinylphosphonic acid (VPA, CH2 CH-PO3H2) was polymerized on poly(acrylonitrile) (PAN) surface by plasma technique, followed by amidoximation treatment to convert the cyano group (–C N) into an amidoxime group (AO, –C(NH2) N–OH). The obtained poly(vinylphosphonic acid)/PAO (PVPA/PAO) was used as an adsorbent in the uptake of U(vi) from seawater. The effect of environmental conditions on the anti-biofouling property and adsorption capability of PVPA/PAO for U(vi) were studied. Results show that the modified PVPA enhances the anti-biofouling properties and adsorption capability of PAO for U(vi). The adsorption process is well described by the pseudo-second-order kinetic model and reached equilibrium in 24 h. Adsorption isotherms of U(vi) on PVPA/PAO can be well fitted by the Langmuir model, and the maximum adsorption capability was calculated to be 145 mg g−1 at pH 8.2 and 298 K. Experimental results highlight the application of PVPA/PAO in the extraction of U(vi) from seawater.Our modified poly(vinylphosphonic acid) (PVPA) enhances the anti-biofouling properties and adsorption capability of poly(amidoxime) (PAO); the PVPA/PAO presents exceptional ability in the selective uptake of U(vi) from seawater. 相似文献
16.
Hitler Louis Daniel Etiese Tomsmith O. Unimuke Aniekan E. Owen Abdulahi O. Rajee Terkumbur E. Gber Chioma M. Chima Ededet A. Eno Emmanuel N. Nfor 《RSC advances》2022,12(47):30365
The application of nickel complexes of nicotinic acid hydrazide ligand as a potential gas-sensor and adsorbent material for H2S gas was examined using appropriate density functional theory (DFT) calculations with the ωB97XD/Gen/6-311++G(d,p)/LanL2DZ method. The FT-IR spectrum of the synthesized ligand exhibited a medium band at 3178 cm−1 attributed to ν(NH) stretching vibrations and strong bands at 1657 and 1600 cm−1 corresponding to the presence of ν(C O) and ν(C N) vibration modes. In the spectrum of the nickel(ii) complex, the ν(C O) and ν(C N) vibration bands experience negative shifts to 1605 cm−1 and 1580 cm−1, respectively, compared to the ligand. This indicates the coordination of the carbonyl oxygen and the azomethine nitrogen atoms to the Ni2+ ion. Thus, the sensing mechanism of the complexes indicated a short recovery time and that the work function value increases for all complexes, necessitating an excellent H2S gas sensor material. Thus, a profound assertion was given that the complex sensor surfaces exhibited very dense stability with regards to their relevant binding energies corresponding to various existing studies. We demonstrate the efficacy of nicotinic acid hydrazide as adsorbent/sensor materials for H2S gas. 相似文献
17.
In this study, cobalt doped graphitic carbon nitride (Co–CN) was prepared and applied as a catalyst to activate peracetic acid (PAA) for sulfamethoxazole (SMX) degradation at neutral pH. PAA could be efficiently activated by Co–CN resulting in the efficient degradation of SMX. Characterization results of fresh and used Co–CN suggested that cobalt was successfully doped in graphitic carbon nitride (g-C3N4) through chemical bonding (Co–N bond) and the surface cobalt species in Co–CN (i.e., Co(ii) and Co(iii)) were the main activators for PAA. Organic radicals (i.e., CH3C(O)O˙ and CH3C(O)OO˙) were proved to be the dominant reactive species for SMX removal in the Co–CN/PAA system by radical scavenging experiments. The increase of cobalt doping content, PAA dosage or Co–CN dosage could accelerate SMX degradation and the neutral condition was highly favorable to SMX removal in Co–CN/PAA system. Co–CN exhibited a good stability and reusability for PAA activation in degrading SMX. Four possible degradation pathways of SMX (i.e., hydroxylation, nitration, bond cleavage and coupling reaction) were proposed in the Co–CN/PAA system according to eight identified transformation products.An efficient advanced oxidation process (AOP) for sulfamethoxazole (SMX) removal: peracetic acid activated with cobalt doped graphitic carbon nitride. 相似文献
18.
Cynthia B. Rivela Rodrigo G. Gibilisco Carmen M. Tovar Ian Barnes Peter Wiesen María B. Blanco Mariano A. Teruel 《RSC advances》2021,11(21):12739
A product study of the reactions of (E/Z)-1,2,3,3,3-pentafluoropropene ((E/Z)-CF3CF CHF) and hexafluoroisobutylene ((CF3)2C CH2) initiated by Cl atoms were developed at 298 ± 2 K and atmospheric pressure. The experiments were carried out in a 1080 L quartz-glass environmental chamber coupled via in situ FTIR spectroscopy to monitor the reactants and products. The main products observed and their yields were as follows: CF3C(O)F (106 ± 9)% with HC(O)F (100 ± 8)% as a co-product for (E/Z)-CF3CF CHF, and CF3C(O)CF3 (94 ± 5)% with HC(O)Cl (90 ± 7)% as a co-product for (CF3)2C CH2. Atmospheric implications of the end-product degradation are assessed in terms of their impact on ecosystems to help environmental policymakers consider HFOs as acceptable replacements.An experimental product distribution study and the atmospheric implications of the reactions of Cl with two fluorinated alkenes is provided. 相似文献
19.
We designed four series of energetic anions by replacing nitro group (NO2) with trinitromethyl group (C(NO2)3) or by inserting N-bridging groups (–NH–, –NH–NH–, –N N–, –N N(O)–) into the bistriazole frameworks. The properties of 40 energetic salts, based on the bistriazole-derived anions and hydroxylammonium cation, were studied by density functional theory (DFT) and volume-based thermodynamics calculations (VBT). It is found that the newly designed energetic salts have good detonation properties due to their larger nitrogen content and better oxygen balance. And one of their corresponding hydroxylammonium salts exhibits better detonation performance (D = 10.06 km s−1 and P = 48.58 GPa) than CL-20 (D = 9.54 km s−1 and P = 43.36 GPa). Moreover, 10 energetic salts not only exhibit excellent energetic properties superior to CL-20, but also have lower sensitivity than CL-20 (h50 = 13.81 cm). In addition, we rationally selected salt B6 from the 10 salts to predict its crystal structure under pressures. By converting energetic molecules with excellent detonation properties into energetic ions, some highly bistriazole-derived energetic salts with both excellent performance and low sensitivity could be developed strategically.We designed four series of energetic anions by replacing nitro group (NO2) with trinitromethyl group (C(NO2)3) or by inserting N-bridging groups (–NH–, –NH–NH–, –N N–, –N N(O)–) into the bistriazole frameworks. 相似文献
20.
Co-ligand triphenylphosphine/alkynyl-stabilized undecagold nanocluster with a capped crown structure
We report the synthesis and crystal structure of novel co-ligand phosphine/alkynyl protected Au nanoclusters, with composition [Au11(PPh3)8(C CPh–CF3)2](SbF6) (1). The gold atoms in the cluster as a capped crown structure subtend C3v symmetry with one deriving from a central icosahedron and 10 peripheral Au atoms, and all alkynides are exclusively σ coordination bonding. The mean core diameter is about 5.1 Å and the overall van der Waals diameter can be estimated to be 20.5 Å. The optical absorbance of 1 in solution reveals characteristic peaks at 384 and 426 nm and a shoulder between 450 and 550 nm.We synthesized novel co-ligand phosphine/alkynyl-stabilized Au nanoclusters with a capped crown structure, and all alkynides are exclusively in the μ1-η1-end-on coordination mode which is unlike the other undecagold system. 相似文献