I tried with heating and without heating but it is not working. They are well mixing in DI water but not in organic solvents.
Dear Muhammad Faizan,
I guess you mean solid S, not from any sulfide.
S is well dissolved by increasing the pH of your medium. The dissolution process occurs by polysulphide formation, increasing with pH increase.
The alkali metal polysulfides arise by treatment of a solution of sulfide, e.g., sodium sulfide, with elemental sulfur:
S2− + nS → S2−(n+1)
In some cases, these anions have been obtained as organic salts, which are soluble in organic solvents in higher pH values.
Synthetic polysulfide polymers occur by condensation polymerization reactions between organic dihalides and alkali metal salts of polysulfide anions:
nNa2S5 + nClCH2CH2Cl → [CH2CH2S5]n + 2nNaCl
In some cases, polysulfide polymers can be formed by ring-opening polymerization reactions.
It is easy to draw a pH dependence curve of Sn2- series.
Best regards,
WNM
Ammonium Tetrathiomolybdate a Mo precursor dissolves well with DMF or NMP...check suitable S agent which dissolve in above solvents.
Dear Muhammad Faizan, in order to give you some useful advice, I think you should be more specific on what type of sulfur and molybdenum presursors you mean.
Wagner Da Nova Mussel Frank T. Edelmann I am using thiourea as sulfur source and hexaammonium heptamolybdate tetrahydrate as a Mo source, I tried ethanol even DMF but Mo source is not dissolving. I even used Disodium molybdate (VI) dihydrate.
Thanks Sunil
Goor Morning Muhammad Faizan, thanks for the information. I will check for alternatives a.s.a.p. today.
Dear Muhammad Faizan ,
let us consider some points:
1) Thiourea is soluble in water, about 137 g/liter at 20 °C, in polar protic and aprotic organic solvents, however insoluble in non-polar solvents.
2) A significant pH dependence of the n-octanol/water partition coefficient (log Kow) is not detected (Govers et al., 1986).
3) The hexaammonium heptamolybdate tetrahydrate has its solubility at pH 4.0-5.5 (25℃, 0.05M in H2O), the Water Solubility of 400 g/L.
4) Both start materials are water-soluble, so you need to work with aprotic organic solvents to avoid HS- and H2S formation as well as Mo hydrolyses.
5) Thiourea, by its way exposed to acidic medium, forms nitrous fumes, sulfur dioxide, and carbon dioxide. In water, the solubility is about 130 g/L, nevertheless in ethanol, only 3.6 g/L at 20 C.
So, you may do the solution of Thiourea (N2H4CS) dissolving it in NaOH solution following by the addition of ammonium heptamolybdate. Depending on the organic you want to include, this solution necessarily would not be a problem.
If you want to synthesize MoS2, as looks like you can do it in basic solutions via a hydrothermal route where both are very soluble by employing ammonium heptamolybdate and thiourea as starting materials; however, you need to post-annealing in an inert atmosphere, like N2 atmosphere at a temperature higher as 450 °C for a long time, about hours, usually 4 - 5 h.
I hope it helps somehow,
WNM
Dear Muhammad Faizan, I think that Wagner Da Nova Mussel already provided a rather comprehensive answer. I also agree with Sunil P. Lonkar in that tetrathiomolybdates should be considered as alternative precursors. In general, you can make your anionic precursors (e.g. molybdates) more soluble in organic solvents by combining them with bulky tetraorganoammonium ([R4N]+) or -phosphonium {e.g. [Ph4P]+) cations. As a typical example, please find attached a reference describing the synthesis of tetraalkylammonium tetrathiomolybdates. These salts are even soluble in dichloromethane. Similar considerations apply e.g. for heptamolybdates. I hope this helps.
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