M. Ballester

Ultraviolet absorption intensities of the secondary (1A1g → 1B2u, 1Lb) band of benzene derivatives in non-polar solvents. Relevant data☆

Abstract The integrated absorptivity and “smoothed” maximum absorptivity of the secondary (1A1g → 1B2u, 1Lb) band for over seventy carefully selected benzene derivatives in isooctane or cyclohexane, as well as the linear expression relating them, are given.

Some remarkable oxidations of 2,3,5,6-tetrachloro-p-phenylenediamine, and products therefrom

The oxidation of 2,3,5,6-tetrachloro-p-phenylenediamine with Cl2 or Br2 in CCl4 containing I2 affords unusual quinoniminium salts displaying remarkable chemical behaviour.

Two new inert carbon biradicals of the triphenylmethyl series. Synthesis, conformation and spin exchange

Abstract The synthesis and some properties of two new “chemically inert” free biradicals, the perchloroethynylene - (III) and perchlorovinylenebis-4-triphenyl - methyl (IV), are described. They correspond to hydrocarbon analogues known to exist, at least predominantly, in a singlet, quinonoid form.

Influence of a free radical substituent on reactivity (reverse effect). Results involving benzylic systems

Abstract The first examples of the influence of the free radical character on the reactivity of a non-radical substituent in the radical molecule (reverse effect) are reported. They include thermolysis, reductive dimerization and bromination, involving radicals related to perchlorotriphenylmethyl.

Perchlorotolane. A new synthesis and its thermal dimerization

Abstract A new synthesis of perchlorotolane (perchlorodiphenylacetylene; I) is described. It dimerizes at high temperature to give perchloro-1,2,3-triphenylnaphthalene (III) and perchloro-2,3,8-triphenylbenzofulvene (IV). Under the same conditions the latter yields perchloro-5,10-diphenylidene(2,1-a)indene (V).

The influence of a substituent with free radical character (reverse effect) on some nucleophilic substitutions involving benzylic systems

The free radical character of the benzyl bromide (1) causes accelerations in the nucleophilic substitution reactions with acetate and with diethyl malonate anions which are interpreted in terms of a change-transfer, biradical configuration for the SN2 transition state.

Nucleophilic substitution on perchloroindane; reactions and structural reassignments

Nucleophilic substitution on perchlorindane (1) with ethoxide ion gives nonachloro-5-ethoxyindane (6), heptachloro-1,1,5-triethoxyindane (7), and 3,5,6-trichloro-4-ethoxy-2-trichlorovinylbenzoic acid (8). The results show that in perchloroindane (1) aromatic chlorines are more susceptible to substitution than aliphatic chlorines. Since this has not previously been realised, structures of the products (6), (7), and (8) given in the literature are incorrect. From these products the following new compounds have been synthesized: pentachloro-5-hydroxyindane-1,3-dione (9), pentachloro-5-ethoxyindane-1,3-dione (10), heptachloro-5-ethoxyindan-1-one (11), heptachloro-5-hydroxyindan-1-one (12) and its sodium salt (13), 2-bromohexachloro-5-hydroxystyrene (14), 2-bromohexachloro-5-methoxystyrene (15), 3,5,6-trichloro-4-hydroxy-2-trichlorovinylbenzoic acid (16), pentachloro-5-hydroxy-1H-inden-1-one (17), pentachloro-5-methoxy-1H-inden-1-one (18), 5,7,8-trichloro-6-ethoxyisochroman-1,4-dione (19), 5,6,8-trichloro-7-ethoxyisochroman-1,4-dione (20), trichloro-4-ethoxyphthalic acid (21) and its anhydride (22), 2,4,5-trichloro-3-hydroxybenzoic acid (25), 2,4,5-trichloro-3-methoxybenzoic acid (27) and its methyl ester (26), 3-bromo-2,5,6-trichloroanisole (28), and 2,4,5-trichloro-3-methoxybenzoyl chloride (29). An unexpected, abnormally easy hydrolysis of a dichloromethylene group in the salt (13) is reported. Some remarkable decarboxylations and ether cleavages in KBr–dimethyl sulphoxide are also described.

Synthesis and properties of perchlorobi-9-fluorenylidene, An exceptionally twisted ethylene

Abstract The synthesis and properties of perchlorobi-9-fluorenylidene, a highly twisted ethylene, are reported. It is a diamagnetic chlorocarbon.