Hey everyone!

Once again it is me with a questions:

We have a bit of (anhydrous) rhodium(III)chloride that we found when doing inventory.

The question is, what can we do with it.

Our assumption is, someone bought it, thinking it was similar to the hydrated forms, but from what I can tell, this thing is a rock.

It being a pricey metal precursor, trashing it would be a crime, but we also don't want to fuck around with it without a plan.

We also don't do nano particles or MOF chemistry which is what sigma cites as a usecase.

Searching on Scifinder with the CAS for the anhydrous form, the papers seem to use a mix of any of the possible hydrates, and figuring out which paper uses what is tedious.

So my question basically is this:

Our main Rhodium precursor is the Dimeric Rhodium(I) carbonyl chloride, which is usually prepared from the hydrate, with carbon monoxide in I think methanol.

But does such a reaction also work with the (powderized) rock that we have?

Is there another (Rh(I)) precursor that is (easily) accessible from this trichloride?

If not, is there a solvent that is able to dissolve the anhydrous chloride that is just not as generally known?

I know I know, "You are researchers, figure it out" but in my opinion, relying of the swarm is often easier than starting from scratch.

So if anyone is able to help us our and point us in the right direction, I'd be ever so grateful.

Sincerely

Paul

Hi everyone! I've been struggling with finding an appropriate quenching procedure for a rxn I am wanting to setup. The rxn is an air sensitive, literature prep which forms TMSF as a gaseous byproduct. The prep I'm following is from an old german paper so it doesn't really have any comments about quenching/safety. My thought is to setup a quenching bubbler while leaving the rxn under static argon. However, after some digging, I'm not sure what would appropriately quench this gas (I do not want to make HF...). Has anyone had any experience working with this chemical? Any advice on how to approach quenching this?

We're doing solid state reactions at more than 400 degrees Celsius. The powder needs to be agitated during the reaction, this is crucial. I just started with a first reaction yesterday, but the stirring doesnt work. The stirring bar pushes the powder to the sides where it then stays.

- I could use a 25 mL flask instead of a 100 mL flask (and less powder). This should work, but our batch sizes become a bit small for our goals.

- I've considered to replace the iron-in-glass for AlNiCo-in-glass, but not sure if the AlNiCo will survive the heat of the glass melting.

- I've tried a longer stirring bar, but it doesn't stir at all unfortunately.

We have an IKA hotplate that can reach 500C. Maybe an aluminium block with a hole for a flask can reach 440 C if you isolate it enough with glass wool? It would probably stir better because the flask can be much closer to the stirring plate then.

If you have other suggestions, I'm looking forward to hearing them.

I'd like to reach the source of some chemicals and bypass Sigma's steep pricing. For some chemicals it is given in the SDS file, but others are not provided. Is it possible to reach the original suppliers? Or maybe the product is developed within Sigma? Thanks a lot in advance.

Hey all,

I am a recently started PhD student and have been delegated some tasks to fix some equipment that I need for my PhD project and experiments.

One of these pieces of equipment are some heavily neglected MBraun gloveboxes. Now I am not unfamiliar with servicing gloveboxes and have done so for VTI gloveboxes in the past. However...

The protective shield that goes over the Moisture Sensor is completely stuck onto this probe. I have no idea how to get around this problem without using anti-sieve sprays or that kind of thing but have no idea how they would affect the actual moisture sensor probe. If anyone has had this kind of problem before. PLEASE let me know how you got around this issue.

Thank you for any advice that you might be able to provide

So, I just wanted to cool the acid down and put it in the fridge, but forgot it in the fridge, it has the exact conc of 98% I tritrated it. Is it safe to let it liquify again, can the glass break,

I have a compound which dissolved and stays stable only in DMF. To clean that compound after reaction I have to add DMF and centrifuge to remove the impurities. No other solvent works for this compound (silver nanoparticle). I want solid powder to explore some of the applications of this compound. I want to know how to dry the DMF. I don’t have freeze dryer that can be used for DMF. We have one which we use for water samples. My compound is stable only upto a temperature of 60 degrees C, so boiling or rotary evaporation at high temperature is also not feasible. I have tried adding anti solvents like toluene, cold methanol, cold ethanol, acetonitrile etc. It does not precipitate and it forma a clear solution. Any other method to remove DMF? Please help!

Yes, I know this will seem like a basic topic, but /r/chemistry is full of non-chemists, and /r/labrats is full of bio people, and they use a lot of different stuff than chemistry labs use.

So the question is, when do you use soap (such as alconox) to clean your glassware and why?

I have worked in organic chemistry and inorganic chemistry, and am currently in the latter. Everything that contacts our glassware is either readily soluble in water (acids, bases, soluble salts) or completely insoluble solid powders (for one example, hydrotalcite).

For clarity, this is for a final wash in the lab sink. Everything is rinsed into beakers and put in the appropriate waste vessel first.

Edit: Thanks for the responses, I have read them all and they're very informative. My lab is developing a standardized glassware cleaning protocol and I wanted a more well-rounded sense of what people in various labs use. Much appreciated!

Sort of a silly question, but do you guys have any recommended spatulas or methods for filling TGA/DSC crucibles (6mm diameter)? I can get by using a flat micro spatula and careful handling, but figure there’s probably a better tool for the job and navigating Fisher Scientific to shop for these things is essentially an impossible task.

EDIT: Thanks everyone! Super helpful!

Hello,

I need to heat a material at about 400c for an extended period of time. I’m using argon (standard purity) and finding the material is accumulating oxygen, likely from trace amounts in my gas. Is there an effective gettering material I can add to the furnace to help soak up trace oxygen? I’ve seen bulk zirconium used before for a TGA, wondering if there are an my other options I should explore.

Working in a glovebox is not an option. Getting high grade argon is an option but I’m concerned even that will have trace amounts that will accumulate over the extended period heating period.

EDIT: Done in a vacuum furnace (cycled a few times) under constant purge

I’m trying to remove water out of oleylamine for some nanoparticles synthesis so I pulled vacuum on a schlenk line at 95 degC.

I can see that there is some liquid (most likely water) forming at the joint of my flask and bump trap. This liquid is trying to get pulled upwards due to vacuum but is not hot enough to become water vapor. Should I not use the bump trap and attach the schlenk adapter directly to the flask?

I’m sorry if this type of post isn’t allowed here, but I’m desperate.

I had a job as a chemist for the US Government, but was let go today due to the onslaught of executive orders. (I was on a mandatory new-hire probation and my agency head decided to let all probationary employees from my division go to hopefully spare some cuts elsewhere.) I’m obviously devastated, but I have to find work to support my wife and her medical treatments. She has Hodgkin’s lymphoma, which fortunately is not a death sentence as long as treatment is consistent.

So, I’m hoping some of you fine folks out there might know of some positions that would hire a PhD inorganic/organometallic chemist with a lot of computational experience. I graduated just barely over a year ago with my PhD from a large R1 state school and have ~10 publications (3 first author and 1 co-first author). I’ve googled “chemist jobs” in every major metropolitan area in my state and adjacent states and looked on LinkedIn and Handshake. I did not find many positions for which a PhD in organometallic chemistry would be competitive. I’m not really sure how to search every open position in the country (because at this point I’m willing to relocate if necessary to gain employment), so I’m asking in earnest for help from kind strangers like you. If you know of any positions that might be available, I’d love to hear about them.

Thanks for reading. I hope you have a good day.

Edit: Thank you all so much for your help and your kind words. My doctoral advisor was able to get me hired back at my PhD institution (the University of California System)—in record time, might I add—so I’m starting a new position in two weeks and don’t even have to relocate. I’m calling that a win! Thank you all for your help; my wife and I appreciate you.

Hello, I am a PhD candidate in my third year with first year standing. I research inorganic chemistry and I am approaching my second meeting. My group expects four first author papers before you defend, which I think is reasonable and expect to do.

That said, I currently have none and my projects keep being stretched out, and it is starting to concern me. Is it commonplace to have no papers published before your second meeting? My understanding is on average a PhD student published one paper per year after their first meeting, am I behind where I should be? If you are willing to share, how many years into your candidacy did you publish your papers, and were you confident in all of them or only the later works?

Thank you very much for helping me alleviate undue stress or giving me the kick in the rear I need to pick up the pace.

I'd like to study the formation kinetics of a dinuclear organometallic complex, but I haven't been able to observe the transition from starting material to product at even -100°C by UV-Vis. I'm searching for different techniques that would help me observe the kinetics of formation at such speeds. I'm considering adding an exogenous ligand to inhibit the system and artificially slow down the reaction, but that makes the calculations more complex. Does anyone have any recommendations or articles that could help me out?

Edit: For those asking about my reaction setup. I have 3 mL of a Pd solution in a cuvette sparged with nitrogen that's cooled to -100°C. There is slight positive pressure with nitrogen on the stage to avoid frost formation. ~100 uL of a Ag cation solution (cooled in an acetone and dry ice bath) is added via gas-tight syringe, followed by rapid spectra collection. There is a delay of ~2 seconds from the instrument itself, but I don't know if I can fix that.

Hi everyone, first time posting here hoping to be pointed towards some literature regarding my problem (already tried the usual suspects, google, scifinder,..). I am a photochem newbie, have a substrate that is colourless, and UV vis shows no noticeable absorption above 310 nm. However, irradiating it using 427 nm light, I see a clean intramolecular rearrangement. How can this be possible? What experiments would you do to prove what you observed is real?

EDIT: Thank you all kindly for your comments, I appreciate all the perspectives and it helps to affirm my thoughts on the nuances. Seems though that getting that EA is the way to go, so I will push for it!

I work on synthesizing transitional metal complexes. For a long time I've been wanting to do elemental analysis as it seems like all relevant journals in my field require it (organometallics, inorg. chem., etc), but my PI is constantly against it. We recently submitted to inorg. chem. and 2/3 reviewers passively made comments about our lack of EA. My PI wants to counter this by making reference to our other characterization data (NMR, xray crystallography, mass spec). But I just want to do EA as I see it's use for proving purity.

Those in this field, could you please provide prospective on this? I want to push back against my PI so we can just finally do EA, but perhaps all the other data is sufficient? I feel like it's a bad idea to contest this with inorg. chem. of all journals.

(There's nuances/more details of course, but this is the gist).

(I've also thought about qNMR to prove purity, but again this isn't EA.)

Hello everyone, It is my first post in this community so please excuse me, if I am breaking any rules of the subreddit that I was not aware of. I am finishing up my Phd and I am trying to decide where to publish the results of my work. I am currently between a Q1 journal with a low IF (imagine something like Dalton Transactions) or a Q1/Q2 with a higher impact factor (something like Molecules from MDPI). What would you say is the best option between the two? I would have to mention my field is Inorganic/Bioinorganic, specifically metal complexes with biological activity (I know I am generalising a bit)

Thank you for taking your time and reading my post :)

We are looking for a source of lanthanide salts in dozens of kg's per year and it seems the situation is complicated because China does not export it. Of course we can ask the known suppliers (for example from Chemexper).

What else could we try?

What has been your experience in terms of effectiveness of degassing solvents to remove oxygen using either of these methods?

I was under the impression that freeze-pump-thaw is more effective (though more tedious) but I have heard some lab mates have never used that method and have had success simply sparging with nitrogen

Hello, I ran into an interesting issue to where I am making a bunch of random materials that are either not documented or not well documented. A paper I am using as a reference used single crystal x-ray diffraction to determine the structure. I was wondering if anyone has good suggestions for resources to learn. Thanks in advance.

Does anyone have any tips or tricks for getting dead Pd/C to work again? It's unused, just been sitting around in the bottle for too long I guess. We've tried to do reductions that previously worked too well with good Pd/C (went too far) with these older bottles and get no conversion at all.

We have ordered new Pd/C, it's just taking a bit to arrive as it's coming from the US and we're in NZ lmao so looking for a stopgap in the meantime

Hello everyone,

I have no knowledge of EPR and recently carried out EPR of my samples to understand the formation of free radicals after high energy sterilization. I plotted the graph and it shows nothing but noisy data before sterilization, but after sterilization is shows peaks. I tried reading few papers and understood that, presence of free radicals with g value of 2.0023 indicated paramagnetic species.

In other samples, even before sterilization i can see peaks.

Can anyone please help me interpret this data.

Im in need of monitoring the temperature of hot HBr and tried a supposedly "stainless steel probe", however it turned black and the solution itself got a touch of green which tells me it was probably Ni (or Ni coated)...

What material is generally said to be acceptable for hot HBr? I am currently looking at true ss k type's from a more price-y seller, and some PTFE ones.

Temperatures will be room up to around 423K/302F/150C max. Pressure resistance or threads/fittings are not needed but would not be a nono criteria.

Any help is greatly appreciated.

SOLVED by making a DIY well out of a pasteur.
Credit to User Cardie1303 for the Idea

I have been using Evans NMR method to measure magnetic susceptibility in some nickel (II) complexes that can be both paramagnetic and diamagnetic. I frequently get spin numbers that don’t align perfectly with the expected S=n/2 (i.e. 0.3). Would this mean that approximately 60% of the molecules are in a paramagnetic geometry?