Synthesis of fluoride garnets {Na3}[M3+2](Li3)F12 (M = Al,Cr, and Fe) from aqueous solution and their properties

The garnet-type fluorides, Na₃M₂Li₃F₁₂ (M = Al, Cr, and Fe) were synthesized as the coprecipitates of ～1 to 10 μm powders from HF solutions. The garnet structures were always obtained under acidic conditions. The incorporation of water molecules into the structure of the Cr and Fe garnets was observed. After heat treatment at 300°C, very small unknown peaks were observed in the X-ray powder pattern in addition to the garnet phase which had a slightly smaller value of the lattice constant than that of hydrous garnets. From the measurement of magnetic properties and Mössbauer effects, the Fe and Cr garnets were found to be paramagnetic with both ions in the trivalent state. Presentation of infrared spectra of the garnets is also included.     

Spectrophotometric and thermal analytical studies on the dehydration of copper(II) sulfate and its double salts

Spectrophotometric (diffuse reflection) and TG-DTA data on the dehydration of CuSO₄ · 5H₂O, Na₂Cu(SO₄)₂ · 2H₂O, M₂Cu(SO₄)₂ · 6H₂O(M⁺ = K⁺, Rb⁺, Cs⁺ and NH⁺₄) and Co₂Cu(SO₄)₃ · 18H₂O are given. Although complete dehydration of CuSO₄ · 5H₂O brings about a striking color change from blue to white, it was found that there is only a slight decrease in the v?_max. of its d-d band in the course of this change, and the total light absorption in the visible-UV region increases at the same time. The dehydration of the alkali metal and ammonium double salts, most of which contain [Cu(OH₂)₆]²⁺ aquo ions (in contrast to the [Cu(OH₂)₄]²⁺ in CuSO₄ · 5H₂O), occurs generally more easily than that of CuSO₄ - 5H₂O, and their v?_max. increases slightly in the change, leading to blue or green anhydrous products, although the formation of a white modification was observed with the potassium salt. It was also found that the v?_max. of the Cu²⁺ ion in the dehydrated cobalt(II) double salt is still lower than that in anhydrous CuSO₄, i.e., the ligand field and/or tetragonality around it is decreased by the presence of Co²⁺ ions.     

Über die Farbstoffe,die spontan zerspringen

Zusammenfassung Es wurde zuerst best?tigt, da? das spontane Zerspringen der zwei Farbstoffe, Orient Soluble Blue OBC und Orient Nigrosine BR durch Absorption von Feuchtigkeit aus der Luft verursacht wird. Der Vorgang des Zerspringens wurde reaktionskinetisch behandelt. Die scheinbare Reaktionsordnung wurde bestimmt und ihre Bedeutung diskutiert.     

Cationic ring-opening transfer polymerization of spiro ortho esters initiated by carbon black

The ring-opening transfer polymerization of spiro ortho esters (SOE) initiated by carbon black was investigated. In the absence of carbon black, no polymerization occurred at all. In the presence of channel black containing carboxyl group, the ring-opening transfer polymerization of SOE was initiated at 50-70°C. to give polyether ester, namely alternating copolymer of epoxide and lactone. The rate of polymerization of 1,4,6-trioxaspiro[4.4]nonane and 1,4,6-trioxaspiro[4.5]decane was considerably small compared with that of 1,4,6-trioxaspiro[4.6]undecane. The activation energy of the polymerization of 2-chloromethyl-1,4,6-trioxaspiro[4.6]undecane was estimated to be 6.0 kcal/mol. The initiating activity of carbon black increased with an increase in carboxyl group content of carbon black. Furnace black that contained no carboxyl group was unable to initiate the polymerization. Furthermore, the carbon black lost the initiating ability of the polymerization upon the blocking of carboxyl group on the surface by the treatment with potassium hydroxide or diazomethane. Based on these results, it was concluded that carboxyl group on carbon black plays an important role in the initiation. During the polymerization, a part of the polymer formed was grafted onto carbon black: the grafting ratio was 10–30%. The mechanisms of initiation and grafting were discussed.     

5-Isoquinolinesulfonamide derivatives. III. Synthesis and vasodilatory activity of 1-(5-isoquinoline-sulfonyl)piperazine derivatives.

On the basis of a hypothesis that cyclization and alkylation of the diamine part in formula 1 may give highly active compounds, a new series of 5-isoquinolinesulfonamide derivatives, shown as formula 2, were prepared from cyclic diamines. Their vasodilatory effects were subsequently evaluated in vivo according to the increase in arterial blood flow after the formulas were injected locally to the femoral and/or vertebral arteries of dogs. Cyclization of the diamine structure in formula 1 gave very potent vasodilators: 6 and 14. Acylation and sulfonylation of terminal amino nitrogen afforded much less potent compounds. In contrast to the hypothesis, alkylation on the ring carbon and the terminal nitrogen of the cyclic amine afforded less active compounds except for compound 11. The most active compounds, 6, 11 and 14, showed more potent vasodilatory effects and more selective activity to the vertebral artery than either trapidil or diltiazem.