Synthesis of a Donor‐Substituted Tris(cyclopropenylio)cyclopropenylium Salt
Synthesis of a Donor‐Substituted Tris(cyclopropenylio)cyclopropenylium Salt
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供体取代的三(环丙烯基)环丙烯鎓盐的合成
DOI：
10.1002/anie.197904731
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发表时间：
1979
影响因子：
--
通讯作者：
H. Wolf
中科院分区：
文献类型：
--
作者：
R. Weiss;M. Hertel;H. Wolf
支持(6)为三[双（二异丙基）环丙烯]四氯酸环丙烯的结构的证据不仅来自它的形成方式和正确的元素分析，而且来自光谱数据的总和。红外光谱显示了外围环丙烯体系在1885 （A′）和1580 cm-′（E′）处的预期特征环振动；中心环的红外主动E'振动由于叠加而不能归属于某一特定波段。重要的结构信息来自紫外光谱。简单的双（二烷基胺）环丙烯体系的最长紫外吸收波长约为225 nm (log~= 4.07-4.32) 1'。和三氟戊烯指示17)显示约250 nm （log E= 4.2）“。”；系统(6)的最长波长为347 nm (log F= 4.52)，这表明存在一个相当扩展的n-系统。在H- nmr光谱中，异丙基质子信号的1∶1分裂表明所有外围二烷基胺基的旋转都受到阻碍[H- nmr: 6= 5.82 (mc, 12H), 8.42/8.52 (d, 36 H； J= 6 Hz), 8.47/8.57 (d, 36 H； J= 6 Hz)](参见。r3b”)。在I3C-NMR光谱中，这种给体基团的旋转位阻更加清晰，其中在烷基的季元（6=-58.8和56.1）和伯C原子（6=-21.4和20.0）中观察到两个单重态，每个单重态的比例为1:1。此外，记录了四元C原子（6=-138.5,-88.9和-120.3）以2:1:1的比例的三个信号，它们被分配到三个环位置a， b， C（见方案2，共振结构C）。位置a和b是根据与一系列双氨基取代环丙烯化合物~[~]的比较而确定的。环丙烯化合物的环C原子的I3C-NMR信号的化学位移[91]似乎是
Evidence supporting the structure of (6) as tris [bis (diiso-propylamino) cyclopropenylio] cyclopropenylium tetraperchlorate comes not only from its mode of formation and its correct elemental analysis but also from the sum of the spectroscopic data. The IR spectrum shows the expected characteristic ring vibrations of the peripheral cyclopropenylium systems at 1885 (A') and 1580 cm-'(E'); the IR-active E'vibration of the central ring cannot be assigned to any particular band owing to superposition. Important structural information comes from the UV spectrum. Simple bis (dia1kylamino) cyclopropenylium systems exhibit a longest wavelength UV absorption around 225 nm (log~= 4.07-4.32) 1'.~~ and triafulvalene dications 17) show one around 250 nm (log E= 4.2)"."; the longest wavelength band at 347 nm (log F= 4.52) in the system (6) establishes the presence of a considerably more extended n-system. The 1: 1 splitting of the signals of the isopropyl protons in the'H-NMR spectrum indicates hindrance to rotation of all peripheral dialkylamino groups ['H-NMR: 6= 5.82 (mc, 12H), 8.42/8.52 (d, 36 H; J= 6 Hz), 8.47/8.57 (d, 36 H; J= 6 Hz)](cf. r3b'). This rotational hindrance of the donor groups is even clearer from the I3C-NMR spectrum, in which two singlets each in the ratio 1: 1 are observed for the quaternary (6=-58.8 and-56.1) and for the primary C atoms (6=-21.4 and-20.0) of the alkyl groups. Moreover, three signals in the ratio 2: 1: 1 are recorded for quaternary C atoms (6=-138.5,-88.9, and-120.3) which are to be assigned to the three ring positions a, b, c (see Scheme 2, resonance structure C). Assignments for positions a and b are based on comparison with a series of bis (dialky1amino)-substituted cyclopropenylium compound~[~'. The chemical shift of the I3C-NMR signals for the ring C atoms of cyclopropenylium compounds [91 appears to