 So, we were discussing about transactinide and also today we will be covering chemistry of some of the transactinides, the only transactinide elements like element number 104, 105 and 106. So, the chemistry of transactinide mostly there are two types of chemistry, one is the gas phase chemistry and there is the solution phase chemistry. The gas phase chemistry is relatively easier because of the very fast transport in case of the gaseous molecules, but in the solution phase chemistry there will be some sort of a separation is required, which I have discussed in the previous lecture, how the automata time chemistry is done. So, the chemistry in the solution phase mostly involves part-selling type of experiments that is ion exchange, chromatography or solvent extraction. So, we will come details of those chemical aspects in the aqueous phase or in the gas phase. While studying the gas phase chemistry, mostly the volatility of the halides or the oxyhalides is studied. Now, these transactinide elements they are part of the porous transition series and the chemistry of these transactinides in the gas phase is always compared with the other elements in the second or third transition series. So, for example, if we are studying the gas phase chemistry of rutherfordium, which is element 104, so we need to study the volatility of rutherfordium chlorocompounds or the bromocompounds that is RFCl4, which is a volatile compound and we compare that with the transition elements like zirconium chloride or hapnium chloride, so that is HfCl4 or ZrCl4. Similar comparison also can be done with the bromide complexes like the ZrBr4 and HfBr4 compounds and the same way we can also compare the volatility of element 105 chlorides or bromides or oxychlorides that is the dubnium compounds with that of the tantanum as well as the niobium compounds. So, in this slide we compare the volatility of these chlorobromo or the oxychloro compounds. The left figure it is the zirconium chloride and zirconium bromide and their volatility is compared with that of the hapnium chlorocomplex as well as the hapnium bromocomplex that is HfCl4 and HfBr4 complexes. As you can see the hapnium chloro and the bromocomplexes are relatively more volatile as compared to that of the zirconium bromocomplexes as shown here the hapnium chloro and hapnium bromocomplexes following the same pattern and their volatility is higher than that of the zirconium chloro and the bromocom compounds. Now coming to the tantanum and niobium compounds you can see that the chlorocom compounds of tantanum and niobium they are more or less same as shown here on the other hand the bromocom compounds having much lower volatility shown in the profiles given here this is for the tantanum bromide and also the niobium bromide compound. Now the oxychlorides again you have the tantanum oxychloride is having much lower volatility than that of the niobium oxychloride which is having more or less similar volatility is that of the niobium bromide. So in a similar manner experiments can be done for the rathafodium chlorocomplexes and also to form their oxychlorocomplexes as given by this equation by reacting with oxygen and this can be compared with that of the zirconium azolyse hapnium complexes. Now how this gas chemistry studies are carried out for the trans actinides? The experimental method is rather simple there are two types of experimentation is done one is the thermochromatography and other one is the isothermal gas chromatography. The early studies the Dubna lab in Russia they used the thermochromatography column which is directly connected to the recoil chamber. So the gas phase chemistry was nothing but a major of the volatility of the compound this method was very simple and also very fast method. So in this case the detection was done by fission track detectors. So basically the thermochromatography as a function of the length of this column which is there basically you have a column and when this volatile compounds are passed from one end so the temperature along this column is changed till it goes from starting from 450 degrees to room temperature in this way going down and then depending on the volatility of the compound they will be deposited and in this inside surface of this tube the fission track detectors are implanted and by taking out the fission track detectors can monitor where exactly the compounds are deposited. I don't know some disadvantages even though this method is so simple but the real-time detection of the nuclear decay of the transactinites as well as their half-life determination that it was not possible. So subsequently this experimentation involved something called the isothermal gas chromatography which is used by this online gas chromatography operators or Olga and this case the reaction products are carried by graphite aerosol and are trapped in the reaction oven where the gaseous such as hydrogen bromide, hydrogen chloride, chlorine, oxygen or SOCl2 etc are passed and are allowed to react with the transactinite atoms which are coming from the reaction chamber where the heavy ion reaction is taking place and the reaction is done at around 900 to 1000 degrees Celsius and after that this transactinite compounds are coming to be collected at this detector system which is called the ROMA which is a nothing but a rotating type of detector system and which is also going to be counted by alpha spectrometry by a set of PIPS detectors. Now in this case the ROMA actually does the counting using the PIPS detector and the retention time of the volatile compounds in this case the chlorobromo or oxychlorocomplexes of the transactinite is determined by using the half life of the radionic light as a clock and the temperature at which the 50 percent platinum yield is observed that is the T50 the retention time is termed as the half life. So that is how the half life can be determined of these gaseous products of the transactinites. Now coming to the aqueous chemistry experiments there are several sophisticated instruments are used for this, this instrument has been designed in a special way such that this transactinite compounds can be separated and also can be detected using a special type detecting system. The first of such instrument is called the automated rapid chemistry apparatus or ARCA. Major part of the aqueous chemistry studies which are reported in the literature they use ARCA which is having basically several miniaturized columns. The columns have 8 millimeter 8 and 1.8 millimeter internal diameter and the typical cycle time is around 40 to 90 seconds and there will be around 20 such columns in a magazine. This ARCA system I can show in a little more clear view as a schematic I can show here where I have the front view as well as the side view as I was showing this is the magazine actually this one is the magazine where you have these columns embedded into the magazine the column has around 8 mm height and a very very small column which are on 1.8 millimeter as the internal diameter and this is the front view of the magazine here and this helium gaseous potassium chloride gaseous system is coming here and it is forming a solution and the solution is passing through this it comes to alternatively to these two magazines which are having the columns it is passing through that in the separately there will be the elven will be coming and the elven will be passing through the column that is how this elven will be coming and would be collected and to this planchette which will be dried and counted by either alpha or gamma spectrometry alpha spectrometry for the transactinide I am gamma spectrometry for the homolose which are like zirconium or hapnium isotopes which are short lived and those are used sometimes to monitor the chemistry in an online method the way the transactinide experiment is done in such case the zirconium hapnium online data can be compared with the rutherfordium online data the similar manner offline experiments are also done taking relatively more stable compounds of zirconium and hapnium or niobium and tantalum or in case of heborium experiments it is molybdenum and transactin isotopes are used and in this case mostly you have this different micro columns in the ARCA system subsequently this has been also upgraded by the Japanese researchers to be called as automated ion exchange separation apparatus coupled with the detection system for alpha spectroscopy which is called as IDA. Now another type of instrument which is used for this fast separation for the transactinide is called the sissac or this is the short lived isotope studies by the aquifer technique. Aquifer is a very fast extraction in this case extraction is by solvent extraction so that it is a aquifer is a solvent extraction system where automatically after equilibration of the organic and the aqua space a part of this mixture will be pipetted out and it will be centrifuged and separated all these things in a very very short time period such that these experiments carried out in several minutes or so in case of the aquifer system and some cases it can be done even faster to go to the second level and there is used for the transactinide separation chemistry studies and this sissac has been developed by the British research groups and they have used this is a system is given where you have actually several extraction as well as centrifuge methods are there this setup is there and you have the aqua space going into this and the gas phase also is going inside this and they will be mixed here and then the degassing can be done and it will go into the extraction as well as the centrifuge stays here where the organic phase will be will be inserted into the this system so fast extraction and centrifuge is done then aqua space will be taken out of the system and the organic phase will be going this way and it will be countered by the liquid circulation counter so this is very very fast system and several experiments have been carried out by this sissac setup which I will be discussing for some of the transactinides now coming to the individual transactinides first let us go to the rathophodium or the element 104 we discussed first the aqua chemistry of rathophodium the major complexes as we know for the actinides and the transactinides are the hydrolyzed species in case of the aqua species so therefore the acidity of the aqua space needs to be controlled with normal pH conditions then we are having the hydrolyzed species so for the group 4 elements like rathophodium and its homologs like zepconium and hafnium we have that these are pH greater than 6 we get the pentahydroxy anionic species which is like this M H2O and then OH I minus this type of species and we can have X number of H2O so this type of species will be formed for the tetravalent metal ions like rathophodium as well as zepconium and hafnium the hydrolyzed species can undergo also complexation here I have shown how this hydrolyzed species can form a complex with complexing agent like Hx where X minus is the anionic species which is forming a complex so the species if it is not having hydrolyzed species then it can form like Mx H2O 7 3 plus that means the tetravalent ion is not having any hydroxocomplex in that case it will form complexes like this and it will continue to form the complexes till it has completely anionic complexes like Mx 6 2 minus so example of this type of complexation is Mf 6 2 minus so that is the fluoride complexes of zirconium hafnium or rathophodium is formed species like Mf 6 2 minus and the hydrolyzed species also can form complexes like I have mentioned here you can have a precipitated form of this tetrahydroxy complexes of the tetravalent metal ions like zirconium hafnium or rathophodium and this precipitate can form complexes with Hx giving Mo Hx plus H2O and subsequent complexation can take place to give Mx 4 type of species. The Mx 4 also can complex with another Hx to give Mx 5 minus and subsequently with another Hx to give Mx 6 2 minus giving species like this I have mentioned now coming to the equischemistry of rathophodium we know that rathophodium is a member of the pore group as shown here so it has an oxidation state of plus 4 and it has anionic size hafnium is having 0.71 angstrom rathophodium 0.78 angstrom and thorium 0.94 angstrom why I mentioned thorium here because thorium is an actinite spirit as mentioned here and this is called as the pseudo homolog of rathophodium the transition elements in the group 4 like titanium and zirconium they are considered as the homolog of rathophodium and thorium 4 plus is considered as the pseudo homolog of rathophodium now based on this anionic size this is for the hexa coordination the fluoride complexation will follow the anionic potential so that is hafnium is greater than rathophodium is greater than rathophodium fluoride is a hard ligand it can form a stronger interaction with the hard cations like hafnium zirconium to some extent rathophodium and so rathophodium forms anionic complexes like RFF6 2 minus and is also prefers to form complexes with the chloride ion based on the hearts of acid base principle because it is relatively softer as compared to hafnium so I have found a figure here where the experiments have been carried out by the arca system and the system contains a small quantity of hydrogen fluoride that is 3 into 10 to the power minus 3 molar hydrogen fluoride and also varying concentration of nitrate that is a nitric acid concentration is varying and the k d values are determined and you can see here that the species which is formed is RF6 2 minus or for zirconium and hafnium it is an f6 2 minus where m is either zirconium or hafnium which increasing nitrate concentration you find that this k d values is decreasing with a negative slope of minus 2 suggesting that the extracted species is indeed mf6 2 minus this type of species are formed and which increasing nitrate ion concentration this k d value is becoming less and less and same type of species was also seen in case of rathophodium your minus 2 species slope here so that suggests that the extracted species mf6 2 minus in this case and the chemistry of rathophodium as shown here is similar to that of zirconium and hafnium also ion exchange studies have been carried out for rathophodium where the studies have been carried out with varying concentration of hydrochloric acid that is a chip and also 0.1 molar nitric acid has been taken in these experiments that is a mixture of nitric acid and hydrochloric acid and the rathophodium was transported using the potassium chloride helium gas the transport system and under cation exchange regime you can see that at the hydrochloric acid concentration of around 10 to the power minus 3 or lower you can find out this k d values are becoming very very large so that means the ionic species are not formed at the cationary complexes their jargon to the cation exchange regime but if you increase the hf concentration beyond 10 to the power minus 3 you find that this k d values are dropping and as shown here the comparison has been done between this uptake of zirconium hafnium thorium and rathophodium using this cation exchange column zirconium hafnium and thorium data are generated by offline method whereas the rathophodium data was generated by online method which is very obvious and you see here that the thorium offline data is actually entirely different than what has been seen for the zirconium and hafnium zirconium hafnium is falling a pattern here and rathophodium is in between rathophodium is falling actually in between that means it is at some experiments it may be falling close to that of the zirconium and hafnium data and some other cases it is lying in between that of thorium as well as zirconium and hafnium so get some more clarification the ion exchange studies were carried out again with offline and in this case some online experiments also were carried out using hafnium so rathophodium experiments are always carried out online but the hafnium data presented here the left hand side figure is both offline as well as online and you can see that this hafnium online data which is the solid circle and the hafnium offline data which is the purple line so on here there are more or less matching and you have the thorium offline data which is lying here which is matching in this case surprisingly with the rathophodium online data you see the triangles are the rathophodium online data so for the cation exchange column experiments the thorium data is matching with that of the rathophodium online data and this experiment was repeated using an ion exchange regime so the experimental condition is same but you have a reverse pattern here in case of the cation exchange regime initially the kd value was low that is that low concentration of hf where the chloride complexation was not there those cases you have the cationic species and we are absorbed into the columns and in case of the anion exchange regime you find that lower concentration of hf because anionic complexes are not formed so the uptake onto the anion exchange regime is not there you find the very low kd values but at higher concentration of hf you find that the anionic species are formed and then you find that the kd values are going up but what is interesting in this case is that though the hafnium offline as well as the hafnium online data they suggest some increase actually with increasing the hf concentration and also which is matching with the zirconium offline data which is shown here the thorium data actually is showing no change at all that means thorium is not forming a flow rate complex and surprisingly the rathophodium also gave the data which are matching with the thorium data points so in the cation exchange as well as the anion exchange experiments with the rathophodium zirconium hafnium and thorium the conclusion was that rathophodium and thorium data points were matching with both the type of region now coming to the sisak experiments with element 104 that is rathophodium in this case the tolerant extraction experiments were carried out with the group 4 elements using cryoctile amine which is a tertiary amine in xylene and the experiment was done from the sulfuric acid medium and as shown here the data of zirconium hafnium and rathophodium all in the tetravalent are the plus 4 oxidation states the distribution ratio values they increase as a function of the TOA that is a trioctile amine concentration and you find the straight line plots in these log-loved plots and the slope value of these lines are around 1.4 and which is more or less consistent for all the three types of metal and suggesting that the mixed type of extracted species are formed that is this extracted species is having either one or two amines so that is how you get a mixed species and the slope value is around 1.4 so this sisak experiment also shows that the pattern of zirconium hafnium and rathophodium if we see that the zirconium extraction is the highest and followed by the hafnium extraction and which is followed by the rathophodium extraction but you find that this rathophodium extraction is comparatively lower than that of hafnium extraction now I come to the element number 105 which is the dubnium and I mentioned here that aqueous chemistry of dubnium dubnium again it is as the homolog vanadium niobium and tantalum it has a pseudo hemolub is the protactinium is a member of the fifth group as mentioned so we have niobium tantalum and dubnium which are forming the same group and the first experiment is carried out in this case was the adsorption on the glass surface from the scl and nitric acid solutions which is again a characteristic of the some of the group five elements fluoride complexion the trend shown here by theoretical calculation taking into consideration their relativistic effects is protactinium should have highest complex formation with the fluoride ion followed by niobium followed by dubnium or niobium and dubnium they may be having more or less same complex formation tendency and tantalums should be having the least complexion with fluoride ion so this was tested by extraction studies using alipod 336 and from six molar chloride solution this extraction followed the order protactinium followed by niobium followed by dubnium followed by tantalum so this confirms the theoretical calculation and the kd values in the offline as well as online measurements for a particular consent condition is given here you see that the kd values around 1440 for protactinium which is very very high compared to that of niobium that is 683 and dubnium value is around 438 and which is again very very large compared to that of tantalum which is only 22 is the kd value of itself you can see that at this condition this kd values are given now another example I give the at least chemistry of dubnium so these studies are carried out using a mixture of hydrochloric acid and hydrochloric acid using arca and the extraction chromatography studies are carried out using trioctile amine as the extractant the extraction of niobium tantalum protactinium which is a pseudo homolog has been taken into consideration and dubnium into isoctile amine from 12 molar HCl and 0.02 molar hydrochloric acid and also from 10 molar HCl studies were carried out and in this case dubnium was found to be extracted together with niobium tantalum and protactinium that means all four elements were extracted together but after the first extraction step the niobium and protactinium fraction was eluted with 4 molar HCl and 0.02 molar HCl and tantalum fraction was eluted with 6 molar HNO3 and 0.0015 molar HCl and the observation was that 80 80 percent of the dubnium was with the niobium protactinium fraction while only 12 percent was with the tantalum fraction that suggests that dubnium is more or less following the similar chemistry of niobium and protactinium fraction now to have a further distinction 10 molar HCl containing 0.025 molar HF protactinium was eluted first and niobium was eluted with a 6 molar HNO3 containing 0.0015 molar HF but then in this case the distribution of dubnium was more or less equal with both these fractions that is around 25 alphabets was seen with the protactinium fraction and 27 is the niobium fraction so that whatever trend is seen from this experiment it does not match with what has been theoretically predicted that means in this case tantalum is having higher extraction followed by niobium followed by protactinium and dubnium is somewhere also very close to that of protactinium the last part in this series is the chemistry of cyborgium cyborgium is known to be member of the six group that is molybdenum and tungsten and it can also have a pseudo homologous uranium so when the experiment is carried out for example the cation exchange column studies using arca have been done where the elution was done using 0.1 molar nitric acid and 0.5 millimolar hydrochloric acid together with the MOO42- and WO42- these are eluted along with the cyborgium suggesting that cyborgium also may be species like SgO42- this type of species anionic species it may be forming but this cyborgium does not follow the chemistry of uranium which was very clearly proven and another experiment was carried out in which 0.1 molar nitric acid was used as the elution and it suggested that cyborgium is different from molybdenum and tungsten also and also based on the hydrolysis it is considered entirely different as compared to molybdenum and tungsten molybdenum tungsten can form this neutral hydroxo species like MO2OH twice but it was reported that cyborgium does not form this neutral type of species and always form a catenate species even at higher PS values. Now this is how I conclude the chemistry of this element 104, 105 and 106 to summarize we see that these results from the recent studies they justify the positioning of the transctenite starting with element 104 into the seventh period of the periodic table and the chemical studies have performed with reciprocidium, dubnium and cyborgium both in aqueous as well as gas phase the heavier transctenites gas phase chemistry also is reported and all experimental results yield properties which place them these elements into their respective groups in the periodic table. A closer look released that their chemical properties cannot be predicted in a comparison with the lighter homologs however the modern relativistic molecular calculations show excellent agreement with the experimental data. Therefore, one can deduce the relativistic effects strongly includes the chemical properties of the transctenites subsequent experiment with element 118 has been also carried out recently these elements 119, 120 and 121 have been identified but need confirmation this will start period 8 in the periodic table and these studies are mostly carried out in the Lawrence Berkeley National Laboratory USA, the Dubna lab in Russia, the GSI lab in Germany and also Rikken Japan. Thank you.