element109 (Hive Bee)
08-22-01 19:02
No 206564
      promotors of Urushibara ??  Bookmark   

I've just read USPAT 3,997,478 ; relating to >Raney-Ni containing as promotor 2 metals selected from the group consisting of Cr, Co, Mo & Mn. These are far more active then conventional raney-Ni containing 0 or 1 foreign metal.

Bull. Soc. Chim Fr. 13,208;1946 describes the effects of Cr, Co & Mo as promotor on the catalyst in amounts between 1-10% b.w. related to the Ni. Each increases the activity of the catalyst.

Is there anyone who has experimented with eg. cobalt-doped urushibara ? If these promotors work equally well with uru-Ni ...laugh

e109
 
 
 
 
    Antibody2
(Hive Addict)
08-24-01 23:40
No 207092
      Re: promotors of Urushibara ??  Bookmark   

The only ref antibody have seen about Cobalt Urushibara is in relation to the hydrogenation of ethylenic bonds for which it is less active but more selective in the hydrogenation of nitriles to amines. and in the supression of unwanted secondary amines starting from nitriles or oximes. Hatta also cautioned against the use of ammonia for thes reductions.FWIW

"All those memories lost like rain..."
 
 
 
 
    element109
(Hive Bee)
09-08-01 15:50
No 211359
      Re: promotors of Urushibara ??  Bookmark   

AB2, I think you are referring to Uru-Co (no Ni) which is probably of no use to us.

You dissolve 40 gr NiCl.6H2O in EtOH, add 3-5% (calculated on weight of Ni) of ammonium molybdate and 3-5% cobalt chloride; and proceed as normal. Al is more electronegative than Ni, Mo and Co so they will all precipitate on the Al.

Now, could this do the same with Uru-Ni as it does with raney-Ni, enlarge (sometimes more than double) the amount of H2 being taken up per minute per gram of catalyst, resulting in faster reaction and higher yields.

I will go today to a supply to buy these two metal salts, to do some pioneering research, only thing we need now is some kind of nitroalkene
wink

e109
 
 
 
 
    PolytheneSam
(Master Searcher)
09-08-01 23:49
No 211468
      Re: promotors of Urushibara ??  Bookmark   

Kieselguhr or diatomaceous/infusorial earth used as a support also seems to increase the activity of nickel catalysts.

http://www.geocities.com/dritte123/Nipat.html

http://www.geocities.com/dritte123/Aminepat.html


http://www.geocities.com/dritte123/PSPF.html
 
 
 
 
    element109
(Hive Bee)
09-09-01 20:31
No 211620
      Re: promotors of Urushibara ??  Bookmark   

Thanks, Sam !
Thanks, Sam !
These lists are full of interesting titles.
 SWIM has already stocked up a buttload of NiCl2, I'm going to research and research to optimize the Urushibara reduction, I really believe this catalyst is being underestimated and the yields could be higher with the right modifications. Anyone tried external H2 input yet ?
I think not only nitroalkenes, but plenty of others (nitriles, imines) could be reduced with satisfaction.



e109
 
 
 
 
    PolytheneSam
(Master Searcher)
09-09-01 21:55
No 211647
      Re: promotors of Urushibara ??  Bookmark   

Good man.  I have some NiCl2, too.  Years ago I electrolyzed some to get Ni metal and tried hydrogenating some vegetable oil in some solvent with H2 in a home brew Parr hydrogenation apparatus.  It took up H2.  These patents look pretty interesting.  I might try out some experiments, myself when I have the time.  One advantage is that you can see H2 being taken up so you seem to have some indication that the process is working. Also note the link http://www.geocities.com/dritte123/PSPF.html in my signature which has links to those pages.
In the first link here Post 210254 (LaBTop: "Microscale hydrogenation", Methods Discourse) there's a picture of a fairly simple hydrogenation apparatus.  I got this idea, too, after seeing a picture of the balloon technique in a chemical experiments book.

http://www.geocities.com/dritte123/PSPF.html
 
 
 
 
    Antibody2
(Hive Addict)
09-10-01 14:20
No 211863
      Re: promotors of Urushibara ??  Bookmark   

element - let us not forget oximeslaugh

"All those memories lost like rain..."
 
 
 
 
    jim
(Hive Bee)
09-11-01 06:05
No 211957
      Re: promotors of Urushibara ??  Bookmark   

I have mused on several occasions about the possiblity of using a Urushibara nickel catalyst in a Catalytic Transfer Hydrogenation process, but using propylhexdrine (C6H11-CH2-CH(NHCH3)-CH3) as the hydrogen donor and no hydrogen acceptor, or possiblely ephedrine as the hydrogen acceptor, thereby making meth from the dehydrogenation of the propylhexdrine, and while you are hydrogenating ephedrine.

Just a thought...
 
 
 
 
    Rhodium
(Chief Bee)
09-11-01 07:48
No 211980
      Re: promotors of Urushibara ??  Bookmark   

That would be really slick. Catalytic transfer hydrogenation between propylhexedrine and ephedrine... Someone will kill you for inventing that idea wink
 
 
 
 
    jim
(Hive Bee)
09-11-01 21:21
No 212188
      Re: promotors of Urushibara ??  Bookmark   

You like that Rhodium?  I have suggested it on several ocassions, but it has repeatiedly fallen on deaf ears.  I got the idea a couple of years ago when I first discovered Urushibara catalysts and brought them to the attention of the HIVE.
 
 
 
 
    Rhodium
(Chief Bee)
09-11-01 21:26
No 212190
      Re: promotors of Urushibara ??  Bookmark   

I think it would be a very cool thing to do (two in one), but I have no idea if it would work satisfactorily, I'm not good at hydrogenation theory.
 
 
 
 
    element109
(Hive Bee)
09-14-01 16:56
No 213511
      Re: promotors of Urushibara ??  Bookmark   

Of course i'll not forgetthe oximes, only need toget hold of some HONH2.HCl, next week probably. There is a synth somewhere of this using sat'd NaNO2 and NaHSO3 solutions.tongue

I've already bought some cobalt powder, and am only waiting for the molybdate. MoO3 seems a lot cheaper tho, but it doesn't react with acid. I suppose ammonium molybdate will do.



e109
 
 
 
 
    Antoncho
(Official Hive Translator)
09-15-01 08:06
No 213783
      Re: promotors of Urushibara ??  Bookmark   

dear element109,

no matter what you buy - MoO3 or (NH4)2MoO4 - you still should reduce it first - at least, molybdate won't react w/acid either. Just combine some molybdate w/Na2SO3 (or some such), slowly add acid, then basify completely, filter the precip'd Mo(OH)2 (i don't know exact Mo's valency here), wash w/water, dissolve in HCl, evap liquid.

Antoncho
 
 
 
 
    PolytheneSam
(Master Searcher)
09-15-01 16:58
No 213836
      Re: promotors of Urushibara ??  Bookmark   

They give examples using ammonium molybdate here.
http://164.195.100.11/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=%274153578%27.WKU.&OS=PN/4153578&RS=PN/4153578


http://www.geocities.com/dritte123/PSPF.html
 
 
 
 
    element109
(Hive Bee)
09-26-01 17:45
No 217381
      Re: promotors of Urushibara ??  Bookmark   

Yes, they say it works in the alkaline medium .
They also use tartrates of Cr and Ti

e109
 
 
 
 
    PolytheneSam
(Master Searcher)
09-27-01 02:15
No 217504
      Re: promotors of Urushibara ??  Bookmark   

I found a mixture of diatomaceous earth and CaCl2 in the hardware store recently for use as a dehumidifier and air freshener.  The diatomaceous earth looks like kitty litter.  ???
The CaCl2 can easily be picked out of the mixture.  Also, it says on the box that it can be regenerated by heating it at 400 C in an oven for one hour.

http://www.geocities.com/dritte123/PSPF.html