四氮化四硫是一种具有爆炸性的物质,受撞击或加热至100℃以上会引起爆炸,在处理产品S₄N₄时应小心谨慎,并且不要将较多的S₄N₄放在一起。
制备方法可以通过以下两种反应制得:
制备反应在装有搅拌器和气体导入管的三颈圆底烧瓶中进行。首先,将50 mL S₂Cl₂ 和100 mL 干燥的CCl₄加入到烧瓶中,在强烈搅拌下通入氯气,直至溶液颜色从黄色变为橙红色且上层有一层明显的绿色氯气层为止。然后,将烧瓶放到流水水浴中,使水平面与瓶内的液面相齐。
在搅拌下向溶液中通入氨气,在不致使反应物溅出和瓶内反应温度不超过50℃的条件下,尽量加大氨气流量。若发现CCl₄有明显损耗,可适当补充。随着反应进行,装置中会覆盖上不少氯化铵。大约经过2小时,当反应混合物全部变成金红色时,取出少量反应混合物与约5倍的水一起摇荡,然后测量水萃取液pH值。若pH>8,则停止通入氨气;否则继续通氨气直至pH>8为止。
将反应混合物用玻璃砂芯漏斗过滤,把所得潮湿固体产物放在1 L水中搅拌5~10分钟。将未溶解的固体物质过滤出来,在空气中干燥1~2天。然后将干燥产物放入萃取滤纸筒中置于Soxhlet萃取器中,用约400 mL 干燥对二氧六环进行萃取,直至萃取液仅呈淡黄色为止。将萃取液冷却至室温,会有少量S₄N₄结晶析出;过滤后在空气中干燥。滤液在温度低于60℃条件下蒸发至干,所得残渣用热苯重结晶以除去硫,两次所获的S₄N₄结晶合并,产量一般可达16 g。
这种化合物也可通过二氯化二硫和氨在四氯化碳溶剂中制备,或在170℃下将二氯化二硫蒸汽通入丸状氯化铵中制得。
用途四氮化四硫是制造其他硫-氮化合物的重要原料。
Electrochemical (polarographic, cyclic voltammetric, and coulometric) and coordination behaviour of several symmetrically and unsymmetrically substituted phosphiniminocyclotrithiazenes have been studied. Polarograms of R3PN-S3N3 (R = C6H5, p-ClC6H4, p-H3CC6H4, and (OC4H8N)), Ph2(OC4H8N)PN-S3N3, and Ph(OC4H8N)2PN-S3N3 give two cathodic waves. Cyclic voltammograms of Ph3PN-S3N3 (1) and (OC4H8N)3PN-S3N3 (2) reveal nearly the same oxidation peak potential but different reduction potentials. Controlled potential electrolysis of 1 and 2 at +0.6 V indicates exocyclic cleavage and ring degradation. Cathodic reduction behaviour of Ph3PN-S3N3 suggests the possibility for the formation of 1,5-(Ph3PN)2S4N4 under electrochemical conditions. Reaction of nickel chloride hexahydrate with heterocycle 1 in 1:2 molar ratio in acetonitrile affords the complex, [Ni(S2N2H)2] (A) (90% yield) and [Ph3PNH2]Cl salt as products. Analogous reactions with other ligands of this type (two symmetrical (sym.) and three unsymmetrical (unsym.)) except 2 also give A, while ligand 2 reacts with anhyd NiCl2 in an equimolar ratio to afford a dark green, square-planar complex ((OC4H8N)3PN-S3N·NiCl2 (B)) whose ESCA results assist in providing its coordination details. The study reveals a high tendency of these heterocycles to different types of ring cleavage. Key words: phosphiniminocyclotrithiazenes, polarography and cyclic voltammetry, substituent effect, nickel complexes, ESCA.