Preparation of complexes of ferrophthalocyanine with imidazole, piperidine, pyridine, and several substituted pyridine derivatives (Rpy where py = pyridine and R = CH3, OH, Cl, CN, CHO) is reported. A metal-to-macrocycle charge-transfer band is characterized in the optical spectra of all compounds in the series. An extra band is observed in complexes with electron-withdrawing substituents on the axial pyridine. Mossbauer measurements on all the compounds have been made, and correlation of Mossbauer parameters with optical data is proposed, d, -* tt* back-donation accounts for the experimental data.

Diacetylene was prepared by the reaction of 1,4-dichloro-2-butyne with sodium hydroxide. Three modifications of procedure were tried to determine which gave the highest yield and purest product. Evidence that the by-product is 2-chloro-2-butene-3-yne is presented. Several methods for purifying the diacetylene were investigated. The ultraviolet spectrum with molar extinction coefficients is given. INTRODUCTIONA sample of very pure diacetylene was required for polymerization and spectroscopic studies. In recent years most investigators have prepared it by the dehydrochlorination of 1,4-dichloro-2-butyne with sodium hydroxide (1, 2, 3, 4, 5) but only one (4) appears t o have reported that the product is not entirely pure. However, no indication of the nature of the impurity was given. RESULTS ISeveral modifications of the dehydrochlorinatio~~ were tried t o determine which gave the highest yield and purest product. T h e yields were highest when 40% aqueous sodium hydroxide solution (285% of theory) was added to a 25Yo solution of 1,4-dichloro-2-butyne2 in ethyl alcohol a t 65-75' over a period of 1 hour (1) and the product was swept o u t of the reaction flaslc with a stream of hydrogen. However, a small percentage of a by-product having a parent peak of 86 in its mass spectrum, as well as tarry high polymers, also formed. When the procedure was reversed and the dichlorobutyne in alcohol was added to the sodium hydroxide, the yield of diacetylene was substantially lower and the fractionated product contained about the same co~icentration of the same impurity. When pure dichlorobutyne was added to 43y0 sodiunl hydroxide solution a t 115', the yield was still lower but the relative amount of the above impurity was lower. Some acetylene and methyl acetylene also formed and were detected by their mass spectra.From the ratio of the 87 t o the 86 mass peak, the spectr~lm indicates that the impurity contains four carbon atoms and the ratio of the 86 to the 88 peak is in goocl agreement with the lcnown ratio of C135 t o C137. I t would thus appear that its empirical formula is CIHsC1. I t also has a strong absorption a t 224 to 245 111p in the ultraviolet and its extinction coefficients are of a higher order thaii those of diacetylene, indicating two conjugated ethylenic groups or an ethylenic together with an acetylenic. From the above evidence, there would appear to be little doubt that this conlpound formed, even in the presence of a large excess of sodium hydl-oxide, by the incomplete dehydrochlorination of the dichlorobutyne and could theoretically have the structure I , 11, or 111.T o establish its identity, its infrared spectrum was obtained and a comparison made of the out-of-plane vibrations of its olefinic hytlrogens with those of four compounds 'Matzuscript

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