Vicky Silviana的实验室

Potassium dichromate(K2Cr2O7) is a typical example of Cr(VI) compounds, which are all strongly oxidizing, extremely toxic and carcinogenic. Thus they are controlled. However such compounds are very useful to bypass the Cr(III) exchange inertness, so we decided to make some. 2Cr3+ + 3[CO3]2- + 3H2O = 2Cr(OH)3 + 3CO2 2Cr(OH)3 + 3ClO- + 4OH- = 2[CrO4]2- + 3Cl- + 5H2O 2[CrO4]2- + 2H+ = [Cr2O7]2- + H2O Attempt 1 20.00g(0.04mol) KCr(SO4)2.12H2O was dissolved in 200mL water to form a purple solution. 8.28g(0.06mol) K2CO3 was dissolved in water and added to that solution. Reaction quickly happened upon stirring, gas evolved and green precipitation appeared. This is Cr(OH)3, and is collected by filtration and washed. Filtration must be done after evolution of CO2 has ceased. This is normally very painful but this time filtration was very fast. Then, the Cr(OH)3 was thrown into some water, 4.48g(0.08mol) KOH was added and 110g bleach(~4% NaClO, ~0.06mol) was added. Base can neutralize the H+ for...

You know, even the Second Hospital cannot contain me... We have gained much knowledge about these compounds so now we just need to deal with specific properties of these elements. Co2+ is very air-stable in weak field ligand environment, and [Co(H2O)6]3+ lies much higher than O2 so air would never oxidize it. However when the field strength increases(even to NH3) Co3+ quickly dominates since d6 is much more preferred than d7 in a low-spin configuration, the latter has an extra electron. Fe2+, on the other hand, is very air-sensitive unless in strongly acidic solution, or with strong field ligands like CN-. Although NO2- is also a strong field ligand, it cannot stop oxidation to hydrated Fe2O3 at all as shown below. Of course, besides oxygen, HNO2 can also oxidize these low-valent complexes, and is much more effective as shown in previous experiments. K2Ba[Co(NO2)6] Mixed acetate solution prepared as the Ni one mentioned before(in fact Co dissolves in H2SO4 even at RT so this is quite e...

Not sure whether I can really achieve this as NaNO2 is the only source material I can use. Ref   ref2   ref3   ref4 The Mn complexes should be unstable so I won't prepare them here. Cd and Hg complexes might be stable but due to their extremely high toxicity we won't prepare them either. Zn and Pb complexes may only exist as solid solution. So, the actual range is quite small. Fe or Co complexes are extremely air-sensitive and would be separated into another page. If B is trivalent, then this is a rather different family and won't be discussed here. K2Ba[Cu(NO2)6] Attempt 1 12.50g(0.05mol) CuSO4.5H2O was dissolved and solution of 6.90g(0.05mol) K2CO3 was added very carefully(gas evolved!), then this was filtered and washed to give basic copper carbonate. Then this was added into a solution of 6.1g(>0.10mol) AcOH in ~80mL water. A very small excess is needed to prevent hydrolysis. After reaction we got a solution with different color than CuSO4 which indicates formation...

Well, as you know, due to some incidents, during the past months my technology has grown very much, so we can try again. In this compound, the O and H2O are cis, unlike the DMAP salt. ref   ref2 The data in the reference(the Manual also copied it) is completely a mess, but I can guess a little. (NH4)2C2O4 + 2NH4VO3 + 4H2C2O4 = 2(NH4)2[VO(C2O4)2(H2O)].H2O + 2CO2 Attempt 1 4.68g(0.04mol) NH4VO3, 2.48g(0.02mol) (NH4)2C2O4 and 10g(0.11mol) H2C2O4 was dissolved in minimal(~30mL) water and boiled until evolution of gas ceased. Solution became blue as demonstrated long long ago. Excess of H2C2O4 can maintain acidity and ensure full reduction, and it can be washed away with EtOH. After cooling to RT ~200mL EtOH was added and shaken. Solution immediately became opaque and black oil separated. The upper layer was poured away and the oil was shaken with EtOH to solidify(a chopstick or something can help you a lot). Then recrystallized with H2O/EtOH multiple times. However we found that while ...

Nitrite([NO2]-) is a common ion that has multiple modes of coordination. Mainly: -NO2 -ONO <O2N Among these, the -NO2 isomer(nitro) is of course the most interesting. As is known to all in organic chemistry, nitro is a strong electron-withdrawing or more specifically pi-accepting group. In coordination chemistry it is also so, for example, [Co(NO2)6]4- is a rather rare d7 low-spin while corresponding [Co(bipy)3]2+ is a normal d7 high-spin. However its properties are still different from other strong field ligands like CO or CN- whose complexes can hardly cross the 18e line. It is said to be a weaker sigma-donor and pi-acceptor than CN- at least for Fe2+. Its sodium salt, NaNO2, is hygroscopic and gradually oxidize into NaNO3 when exposed to air. It is rather hard to prepare, but can be bought. Although online shops has withdrawn it due to an all-known reason, it is in fact still possible to buy if you are careful enough. I bought a pack due to the same reason. It is commonly used as...

没有【数据删除】，我什么都不是！ ↑ignore this Discussion This complex can be considered as a Fe(II) complex with an NO+ ligand, and as is known to all the Fe(II) complex of Bl- is very stable, not controlled and can be easily bought(or even synthesized from blood and K2CO3), so it is used as source material. This is the first one in this series that does not require KBl as source material. It should be mentioned that while the "NO+ complexes of M(I)" are mostly NO- or [NO]3- complexes since they do not react with bases and cannot be reduced by NH2OH(in fact they are made from these stuff), this complex is mostly NO+, as +2 is already a stable state while +1 obviously has too much electrons and must be donated to something. Little is known about the Mn(II)-NO+ complex, though, and its synthesis requires alternative pathways from Mn(I), as conditions below obviously destroy corresponding [MnBl6]4-. Its NO+ gives it many interesting properties, mainly due to its electrophilicity and oxidating p...