Synthesis and reactions of mixed halogenobuta-1,3-dienes

Abstract

The N = 2 and N = 3 series of the 1 P c doubly excited helium states are investigated by a partial-wave analysis, and by inspecting the one-body densities and the shape-densities. Many features in the anisotxopism of the electronic cloud, in the geometric configuration, and in the details of radial-radial correlation are found. A comparison between the x P e and 3 P S states is made. I. IntroductionThe investigation of electron-electron (e-e) correlation is a basic task of atomic physics. Since helium is the simplest atom with e-e correlation, it deserves to be investigated in detail. In our recent papers^1-4 !, the 1 S", 3 S e 1 P°, 3 P° and 3 P e doubly excited helium states have been explored in detail. The present one is a continuation of previous paper dedicated to the 1 P e states. The interest, just as before, is not in the quantitative aspect, but in the qualitative features of the structures. The same procedure as in Ref.[1] is used to diagonalize the Hamiltonian in a model space to obtain the eigenenergies E{ and the eigenwavefunctions $,-. Only the results of N = 2 and N = 3 series (N labels the shell of the inner electron) are reported in the following.Let us first list some features arising from the symmetry inherent in the 1 P e states: i) Let /,-be the orbital angular momentum of the i-th electron (e,), then we have ^ = / 2 ^ 0. ii) In the (K,T) A classification scheme' 5 ' 6 !, T is now an exact quantum number (in general it is mostly not exact) and T = 1. iii) Let L be the total orbital angular momentum, and M its Z-component. In the following discussions, we fix M = \L\; it implies that we have L essentially lying along the Z-axis. Under this prescription, the probability of both electrons staying in the XY plane is zero. The above three points are common in both the 1 P e and 3 P" states, but different from the odd parity i '+ 1 p° states. In the later, the electrons prefer lying in the XY plane, iv) In the (K, T) A scheme, A is now an exact quantum number (in general it is mostly not exact) and A = "-". v) The probability of both electrons having the same distance apart from the nucleus (i.e., r*i = r 2 ) is zero. The above points iv) and v) are in contrary to the 3 P e states. The later has A -"+", and r\ = r 2 is available. The proof of the above features is referred to Ref. [8], these features are helpful in understanding the following results. II. Energy Spectrum and the Weights of Partial Wave ChannelThe first column of Table 1 gives the n (/-ir,T)jv notation to specify the states, N (n) is the shell where the inner (outer) electron stays. It is evident that K = 0 is in the N = 2 series, and K = ±1 in the N = 3 series. The second column gives the energies calculated in this work to be compared with those in the fourth column by Lipsky^, two sets of energies are in general one-to-one close to each other. The third column gives e,-defined in Ref.[2] to roughly 'The project supported by National Natural Science Foundation of China.

The Vinylic SN Reactions of Nitrodienes with Heteroatom‐Substituted Nuchleophilies and Their Structural Studies

“…Polyhalogenated‐3‐nitro‐1,3‐butadienes 1a–b are a valuable precursor for various synthetic applications. In the course of our studies concerning polyhalogenated nitrodienes, in many cases pentachloro‐3‐nitro‐butadiene 1a and (1 Z )‐1‐bromo‐tetrachloro‐3‐nitro‐butadiene 1b proved themselves as appropriate precursors for a diverse variety of synthetically and/or physiologically interesting compounds. Especially, 1,3‐butadienes are often the starting materials of choice, due to its stepped reactivity in S N Vin processes.…”

“…Especially, 1,3‐butadienes are often the starting materials of choice, due to its stepped reactivity in S N Vin processes. The nitrodiene compounds 1a and 1b used as the starting materials were obtained from the direct nitration of the corresponding dienes according to the literature . The reactions of 1,1,2,4,4‐pentachloro‐3‐nitro‐1,3‐butadiene 1a and (1 Z )‐1‐bromo‐1,2,4,4‐tetrachloro‐3‐nitro‐1,3‐butadiene 1b with molar equivalent of cyclopenthylmercaptane 2 in dichlorometane at room temperature furnishes 3a (88% yield) and 3b (87% yield) as main products (diene/thiol/CH 2 Cl 2 = 1:1:1) (Scheme ).…”

“…The reactions of 1,1,2,4,4‐pentachloro‐3‐nitro‐1,3‐butadiene 1a and (1 Z )‐1‐bromo‐1,2,4,4‐tetrachloro‐3‐nitro‐1,3‐butadiene 1b with molar equivalent of cyclopenthylmercaptane 2 in dichlorometane at room temperature furnishes 3a (88% yield) and 3b (87% yield) as main products (diene/thiol/CH 2 Cl 2 = 1:1:1) (Scheme ). The regiospecifity is caused by the fact that the LUMO of 1a–b is located preferentially at the dihalogeno‐nitrovinyl fragment and to extent of 67–90% at the C‐4 carbon atom . Therefore, independent of the nucleophilicity of the thiol derivatives, the first substitution reaction always takes place at the C‐4 positions of compounds 1a–b .…”

“…1,1,2,4,4‐Pentachloro‐3‐nitro‐1,3‐butadiene 1a was synthesized from 3 H ‐pentachlorobuta‐1,3‐diene with a solution of 63% HNO 3 –98% H 2 SO 4 (10:1) (Riedel‐de Häen, Germany) according to the related literature . The nitration of a mixture of two geometric isomers of (1 Z )‐1‐bromo‐1,2,4,4‐tetrachloro‐3‐nitro‐1,3‐butadiene 1b with concentrated 63% HNO 3 occurs at the dichlorovinyl group by electrophilic substitution of the H atom by the nitro group with the formation of a mixture of ( E ) ‐ and ( Z ) ‐ isomers 1b in ∼45% yield .…”

Dibutadienyl Piperazine, Dibutadienyl Homopiperazines and Butadienyl-Substituted Piperidines From Monosubstituted Halodienes

“…[6][7][8][9] It was known that N-, N,N-substituted dienes were obtained from the reactions of nitrodienes and some nitrogen nucleophiles. [10][11][12][13][14] We have reported the reactions of some thiosubstituted nitrohalodienes and N-nucleophiles before. [15][16][17][18] The aim of this work was to synthesize novel compounds from the reactions of some aromatic and aliphatic monosubstituted nitrodiene compounds with homopiperazine and derivatives of piperazine and piperidine, and also to establish the structure of these novel compounds.…”