For the purpose of confirming the constitution of the polybromo-compounds obtained directly from biphenylene oxide by bromination, the following experiments were performed by the present author: (1) Verification of the formation of 2,3,6-trinitro- and 1,3,6,7- and 2,3,6,7-tetranitro-biphenylene oxides from 3,6-dinitrobiphenylene oxide and of the formation of 2,3,6-tribromo- and 1,3,6,7- and 2,3,6,7-tetrabromo-biphenylene oxides from 3,6-dibromobiphenylen oxide. (2) Isolation of 2,7-dibromobiphenylene oxide from the bromination products of 2-bromobiphenylene oxide, and preparation of 1,3,6,8,-tetrabromobiphenylene oxide from 3,6-dibromo-1,8-dinitrobiphenylene oxide. (3) Comparative studies on the characteristics and the absorption spectra of biphenylene oxide and its bromoderivatives.
(1) The gelation time of the system of tung oil and linseed oil was measured at 240–310°C. In the range of 240–280°C. the lines of 1⁄t−x converge on one point. (2) The relation between gelation time and the amount of addition of any fatty oil is expressed by 1⁄t=1⁄t0−ax, and the value of x at t=∞ is considered as a characteristic constant of added fatty oil. (3) Gelation preventing effects of various natural fatty oils were measured at 270 and 280°C. Drying oils are less effective than non-drying oils due to their tendency of polymerisation. (4) The temperature dependance of gelation time was discussed.
By polarimetric observations with regard to the effects of H3BO3, Na2B4O7 and KBO2 on various polyoxy compounds the following results and conclusion were obtained. Boric acid has a very feeble ability for complex formation with non-ionizable polyoxy compounds, such as mannit and glucose, while alkali borates show strong activity upon them. The order of the strengths is H3BO3<<Na2B4O7<KBO2. Complex is formed between borate ion and polyhydric alcohols. Its quantity increases with increasing BO2′. The effects of boric acid and alkali borates on ionizable polyoxy compounds, like tartaric acid and its salts, appear somewhat complicated. In this case complex formation is possible to a large extent between free boric acid and free tartaric acid (complex I). Complexes are also formed between alkali borate and alkali tartrates (complex II), but they (II) are different in structure from those formed in acidic medium (I). The complex I is formed by the action between BO2′ and alcoholic OH groups, but complex II between B(OH)3 molecule and COO′ ion. Calcium gluconate behaves toward boric acid and borates like alkali tartrates. H3BO3 combines with the COO′ group of the gluconate, while BO2′ reacts with its alcoholic OH groups. Thus it has been shown that the complex formation is in general based upon the reaction between molecule and ion, and not between neutral molecules nor between ions.