Uniaxial magnetic anisotropy is an essential property that governs the performance of dysprosium metallocene single‐molecule magnets (SMMs). Determining this property using experimental methods is necessary and important as it provides direct information vital to the understanding of the magneto‐structural correlation and a valuable reference for theoretical analysis, but has been proved extremely challenging. Herein, we investigate a family of dinuclear dysprosium metallocene SMMs bridged by the methyl and halogen groups [Cp’ 2 Dy( μ ‐X)] 2 (Cp’ = cyclopentadienyltrimethylsilane anion; 1 : X = CH 3 − ; 2 : X = Cl − ; 3 : X = Br − ; 4 : X = I − ). For the first time, the magnetic easy axes of dysprosium metallocene SMMs are experimentally determined, confirming that the orientation of them are perpendicular to the equatorial plane. While the orientation of magnetic easy axis for 1 deviates from the normal direction (10.3°), due to the stronger equatorial interactions between Dy III and methyl groups. Moreover, its magnetic axes show a temperature‐dependent shifting, which is caused by the competition between the exchange interactions and Zeeman interactions. The fluorescence, specific heat studies and ab initi o calculations reveal the significant influences of the bridging ligands on their low‐lying exchange‐based levels and consequently low‐temperature magnetic properties. This work proves the role of equatorial interactions on the magnetic anisotropy and provides insights to design high‐performance dysprosium metallocene SMMs.
https://ift.tt/2ycmSre
I don't understand why ziegler-natta type (sometimes just ziegler) are unable to make linear polymers of this length. What does a metallocene do to prevent the growing polymer chain from dissasociating with the catalyst, that a plain Ti based species can't do?
So I live in Boulder Colorado and have been working at a specialty chemical plant for a little over two years. I have a BA in chemistry and biochem and would like to get my masters in chemistry or material science soon. I have tons of analytical experience from my current job and with it I have done a lot of consulting in the cannabis industry before and after it became legal in Colorado.
Recently I have been offered a job by a friend who started a natural extraction company(super critical CO2). They have a big client who buys cannabis extracts from them and they need science oriented people to run the analytical lab. The job is located in California and my title would be analytical lab manager. With out going into too much detail, the job offer pays slightly better than my current one and they have offered to pay moving expense and any thing else associated with the transition to California.
So I really only have one question, but I'm would love to hear opinions:
- Do you think taking this job could hurt my future job prospects/grad school? Like having a "stain" on my record!
I am down to the wire with a project and am troubleshooting some issues I've been having with Gaussian. I am trying to compare bond lengths, IR absorbance bands for various metallocenes comparing my calculated values to literature values. I ran Ferrocene and its chromium, vanadium, cobalt, and nickel analogues on our cluster and obtained reasonable results with the 6-31g basis set. I did not realize though that when I went to show the MO surfaces that option is greyed out. The cp-M bonds are also not shown after calculation. I reran on my PC and got the same results. Water and nitrogen come out fine though. Does Gaussian have trouble with metallocenes?
Phil
Sudden Lee
Go post NSFW jokes somewhere else. If I can't tell my kids this joke, then it is not a DAD JOKE.
If you feel it's appropriate to share NSFW jokes with your kids, that's on you. But a real, true dad joke should work for anyone's kid.
Mods... If you exist... Please, stop this madness. Rule #6 should simply not allow NSFW or (wtf) NSFL tags. Also, remember that MINORS browse this subreddit too? Why put that in rule #6, then allow NSFW???
Please consider changing rule #6. I love this sub, but the recent influx of NSFW tagged posts that get all the upvotes, just seem wrong when there are good solid DAD jokes being overlooked because of them.
Thank you,
A Dad.
So far nobody has given me a straight answer
I am currently in the hospital. I had a back operation yesterday. The surgical nurse came in my room and started asking questions about my back. She asked me if I had any falls during the last year. I responded just one. It was after summer.
She laughed and said in 20 years of doing this she never was told that joke.
..... Will get a reward.
Because they work on many levels
Well, toucan play at that game.
Argon does not react.
The single‐molecule magnets (SMMs) [Cp′2Dy(μ ‐X)]2 (Cp′=cyclopentadienyltrimethylsilane anion; X=CH3−, Cl−, Br−, =I−) are investigated. For the first time, the magnetic easy axes of dysprosium metallocene SMMs are experimentally determined, confirming that they are oriented perpendicular to the equatorial plane which is made up of dysprosium and bridging atoms.
Abstract
We investigate a family of dinuclear dysprosium metallocene single‐molecule magnets (SMMs) bridged by methyl and halogen groups [Cp′2Dy(μ ‐X)]2 (Cp′=cyclopentadienyltrimethylsilane anion; 1 : X=CH3−; 2 : X=Cl−; 3 : X=Br−; 4 : X=I−). For the first time, the magnetic easy axes of dysprosium metallocene SMMs are experimentally determined, confirming that the orientation of them are perpendicular to the equatorial plane which is made up of dysprosium and bridging atoms. The orientation of the magnetic easy axis for 1 deviates from the normal direction (by 10.3°) due to the stronger equatorial interactions between DyIII and methyl groups. Moreover, its magnetic axes show a temperature‐dependent shifting, which is caused by the competition between exchange interactions and Zeeman interactions. Studies of fluorescence and specific heat as well as ab initio calculations reveal the significant influences of the bridging ligands on their low‐lying exchange‐based energy levels and, consequently, low‐temperature magnetic properties.
https://ift.tt/2ycmSre
