2,7-Substituted Hexafluoroheterofluorenes as Potential Building Blocks for Electron Transporting Materials
摘要:
A series of 2,7-substituted hexafluoro-9-heterofluorenes was synthesized via nucleophilic aromatic substitution (SNArF) reactions of phenyllithium, thienyllithium, and lithium phenylacetylide with various octafluoroheterofluorenes and 2,2'-dibromooctafluorobiphenyl. These compounds are of interest as possible building blocks for materials with useful electron transport properties, since they possess relatively low LUMO energy levels. The HOMO-LUMO energy gaps, as determined by UV-vis spectroscopy, range between 3.0 and 3.9 eV, while photoluminescence emission spectra reveal lambda(ems) values in the range of 365 to 420 nm (corresponding to ultraviolet to violet/blue emission). Dilute solution state quantum yields vary significantly with the nature of the heteroatom and the 2,7-substituents, and approach unity for a number of the di(phenylethynyl) derivatives. The experimentally determined LUMO energy levels (-2.7 to -3.3 eV as determined by differential pulse voltammetry) suggest that these compounds may be good candidates for electron transport applications. Single-crystal X-ray analyses of a number of compounds revealed cofacial packing in all cases, with intermolecular distances as short as 3.4 angstrom.
Palladium-catalyzed double cross-coupling reaction of 1,2-bis(pinacolatoboryl)alkenes and -arenes with 2,2′-dibromobiaryls: annulative approach to functionalized polycyclic aromatic hydrocarbons
This study demonstrates that the doublecross-coupling reaction of 1,2-bis(pinacolatoboryl)alkenes and -arenes with 2,2′-dibromobiaryls proceeds smoothly with the aid of a catalytic amount of Pd(PPh3)4 in the presence of excess base to give a variety of polycyclic aromatic hydrocarbons, such as phenanthrenes, [5]helicene, dithienobenzenes, triphenylenes, dibenzo[g,p]chrysenes, and triphenyleno[1,2-b:4
这项研究表明,在催化量的Pd(PPh 3)4存在下,1,2-双(频哪醇硼基)烯烃和-芳烃与2,2'-二溴联芳基的双交叉偶联反应可以顺利进行。过量的碱可得到各种多环芳烃,例如菲,[5]螺旋烯,二硫代苯,三苯撑,二苯并[ g,p ],和三苯并[1,2- b:4,3- b ']二噻吩好到高产。值得注意的是,使用2,2'-二溴八氟联苯作为亲电试剂的环化反应提供了否则难以合成的八氟菲和半氟化二苯并[ g,p] chrysenes高产。
The effect of locking π-conjugation in organoboron moieties in the structures of luminescent tetracoordinate boron complexes
the spiro geometry of the boron atom, borafluorene and ligand units are perpendicularly aligned, which considerably affects the flexibility of the molecule as well as its solid-state structure. Through comparative analysis with close diphenyl analogues, we show how these structural features influence the thermal, photoluminescent and charge mobility behaviour of the studied compounds. Crystal structural
An unambiguous synthesis of heptafluoro-2-methoxydibenzothiophen (7) is reported. Structures for the products of substitution by MeO− in octafluorodibenzothiophen (1), octafluorofluoren-9-one (3), and the related octafluoro-2,2′-dihydrobiphenyl (4) and 19F NMR assignments are amended. Orientation of nucleophilic substitution in 2,2′-dibromooctafluorobiphenyl is established. The results of competition
Highly Stable and Strongly Emitting <i>N</i>-Heterocyclic Carbene Platinum(II) Biaryl Complexes
作者:Dominik Suter、Luuk T. C. G. van Summeren、Olivier Blacque、Koushik Venkatesan
DOI:10.1021/acs.inorgchem.8b00564
日期:2018.7.16
ligand were synthesized and structurally characterized by 1H, 13C, 19F, and 195Pt NMR, singlecrystal X-ray diffraction, and HR-ESI-MS studies. Detailed photophysical investigations carried out reveal a strong influence on the excited-state properties exerted by the electronic nature of the N-heterocyclic carbenes as well as the fluorine functional groups on the ancillary biphenyl moiety. The solid-state
具有电子不同的N-杂环碳烯的C ^ C环金属化铂(II)三重态发射体- (1,3-二异丙基-4-(三氟甲基)-咪唑-2-亚基(d),1,3-二异丙基-苯并咪唑-2-合成了亚吡啶(e)和1,3-二异丙基-咪唑-2-亚苄基(f)-作为中性配体,联苯(bph)及其氟化衍生物八氟联苯(oFbph)作为双阴离子环金属化辅助配体,并进行了结构表征通过1个H,13 C,19 F和195Pt NMR,单晶X射线衍射和HR-ESI-MS研究。进行的详细光物理研究表明,N对电子性质产生的激发态性质有很大影响。-杂环卡宾以及辅助联苯部分上的氟官能团。所有配合物的固态结构在铂中心周围都显示出近乎平坦且略微扭曲的正方形平面几何形状。与bph类似物的高度结构化发射曲线相比,将氟基团引入配体骨架会导致聚甲基丙烯酸甲酯(PMMA)薄膜中以513 nm为中心的结构化发射减少。此外,在吸收和发射曲线中发现了大约10–12 n
Perfluorophenyl derivatives of the elements
作者:S.C. Cohen、A.G. Massey
DOI:10.1016/s0022-328x(00)83172-1
日期:1967.12
The preparations and reactions of several 2,2′-disubstitutedoctafluorobiphenyls and heterocyclic organometallic derivatives of Group IV elements and titanium are described. Some evidence is given for the organometallic titanium intermediate postulated in the coupling reaction for the syntheses of polyfluorobiphenyls.