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Questions tagged [organometallic-compounds]

For questions relating to organic compounds which contain a bond between a carbon atom and a metal.

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Is it safe to lyophilize/Freeze-dry a chelated compound?

I have a compound that consists of a metal ion chelated by a linear organic structure with assorted moieties in aqueous medium. I'd like to dehydrate this mixture fully to get solid product, but ...
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Why do aromatic compounds have an upfield shift upon coordination to metals?

Why do aromatic compounds have an upfield shift upon coordination to metals e.g. ferrocene? The 1H NMR shows a single environment at ~4.1 ppm. This is in contrast to the usual aromatic shift of ...
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718 views

What would happen if the reaction of reduction of carboxylic acids by LiAlH4 is carried out in alcohol?

Which is the intermediate compound in the reduction of carboxylic acids by $\ce{LiAlH4}$ and what would happen if the reduction of carboxylic acids is carried out in alcohol? From my knowledge I know ...
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259 views

electron counting for transition metal-oxo ligand compound

Using donor-pair method, how many electrons would an oxo ($O^{2-}$) ligand contribute? I cannot decide if it is 2 or 4.
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Why does magnesium prefer to insert into C–Br bonds over C–Cl bonds?

In the formation of a Grignard reagent from a compound possessing both bromine and chlorine, magnesium preferentially inserts into the C–Br bond over the C–Cl bond. For example, the formation of a ...
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How can organocuprates generated with catalytic Cu(I) be competitive in 1,4-addition to an enone?

Organocoppper compounds (e.g. $\ce{LiCuR_2}$) are often prepared from an organolithium or Grignard reagent when a soften nucleophile is needed, such as for a conjugate addition to an $\alpha,\beta$-...
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Treatment of ketones with excess Tebbe reagent

The reaction in black below was presented in a set of lecture notes as an example of the use of the Tebbe reagent, however it's not immediately obvious (to me, at least) that the product should be the ...
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247 views

Why do catalysts have limited turnover numbers in practice?

I quote the Wikipedia page definition for Turnover number: In other chemical fields, such as organometallic catalysis, turnover number (abbreviated TON) has a different meaning: the number of moles ...
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I found transition states (TS), but calculations aren't supported by experiment. Do I look for more TSs or somewhere else?

I'm using Gaussian to investigate a catalyst system. Experimental evidence showed that one of three analogues (R = phenyl, Ph), yielded a benzosultam when treated with 2,4,6-...
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139 views

Regioselectivity in Ziegler–Natta polymerisation of α-olefins

Why does the Ziegler–Natta polymerization display the regioselectivity shown in the image? Internal nucleophiles (coordinated to the metal) should attack the alkene on the less substituted end, like ...
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Are there any stable complexes where an (N-unsubstituted) imine is bound eta^2 to a (late) transition metal?

I've been looking for an example of a stable complex where a $\ce{C=N}$ is coordinated $\eta^2$ to a (late) transition metal, but could not find any. Do they exist at all? For $\ce{C=C}$ there are ...
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Cycloaddition of Silyl Dienol Ethers with Sodium Bromodifluoroacetate: What's the scope?

I have recently came across this article "Copper(I)-Catalyzed [4 + 1] Cycloaddition of Silyl Dienol Ethers with Sodium Bromodifluoroacetate: Access to β,β‐Difluorocyclopentanone Derivatives". (Org. ...
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380 views

Sodium Naphthalenide

The sodium fusion test done in the lab for the systematic identification of a given organic compound is basically fusing sodium metal in a fusion tube, and then adding the compound in a small quantity,...
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Can 0-Carborane be stored at room temperature?

I am a physics post-doc at Oak Ridge National Lab (with a bit more training in chem than the average physicist). I ordered a small sample of o-Carborane from Sigma-Aldrich to test for doping liquid ...
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Do Sodium Alkynides react with esters in the same way that Grignard reagents do?

We know that Sodium alkynides react with aldehydes and ketones like Grignard reagents. But do they behave the same way with esters?
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Mechanism for reaction of an allene with the Grignard Reagent(RMgX)

How does the Grignard Reagent($\ce{RMgX}$) react with an allene $\ce{CH_2=C=CH_2}$ and what are the products formed? This is exactly what I tried to do. Any help will be appreciated.
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Synthesis of a tungsten carbene bromide from [CpW(CO)3]-

I'm currently working through past test and exam papers in order to prepare for my organometallic test at the end of the month, but unfortunately I've gotten stuck on the following question. Since I ...
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576 views

Iodine/ Magnesium Exchange reaction?

Traditional Grignard reagents are made by reacting alkyl halide with Magnesium metal. However, the preparation and scope of their application have been limited because of low functional group ...
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323 views

Why doesn't beta hydride elimination happen in alkenyl/aryl halides?

Beta hydride elimination is an important reaction in organometallic chemistry: This reaction prohibits the use of saturated alkyl halides in coupling reactions, because it can take place after ...
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1k views

Classes of Organometallic Compounds - Where do I put Grignard Reagents?

[Note- I've already seen this question Why do Magnesium and Lithium form *covalent* organometallic compounds? as user Mithoron was kind enough to point out, but the problem that I face is different ...
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443 views

Trends in the covalency of bonding across the transition metals

I am under the impression that the covalent character in the bonding of transition metal compounds increases across a group; in fact I think this is why they're called transition metals (a transition ...
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Why does LDA solution gradually turn dark brown?

LDA (lithium diisopropylamide) solution in THF/hexane gradually turns red-brown liquid. Especially commercially available one is extremely dark red-brown. What makes it brown? I've searched online ...
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How to calculate the magnetic exchange coupling in a charged radical complex?

I have a neutral complex with two magnetic centers. For this case it is easy to calculate the exchange coupling as the broken symmetry state is converged properly. But when I am making the complex ...
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What makes dimethylmercury ((CH3)2Hg) so penetrative through latex and human skin?

I've read the story of Karen Wetterhahn and how she was poisoned and died from two drops of dimethylmercury that accidentally fell on her latex glove, and I was wondering what is the chemical ...
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Selectivity of olefin cross-metathesis reaction

I'm looking at the reaction shown below which uses a ruthenium catalyst: I am confused because the ruthenium catalyst which is used in the reaction should be Z selective due to the features on the ...
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289 views

Selectivity in Suzuki coupling of 2,4-dichloropyrimidine

I've seen many papers (see e.g. Synthesis 2010, 16, 2721–2724) in which the 4-chloro group of 2,4-dichloropyrimidine is selectively reacted under Suzuki coupling conditions. Is there any way where ...
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Shelf Life of Methylcyclopentadiene

We are making organometallics in the lab, but instead of just regular Cyclopentadiene dimer, we crack methylcyclopentadiene dimer to make methylcyclopentadiene. I cannot find the shelf life of ...
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54 views

Why does Pb(II) promote ligand substitution?

I have heard of an article where divalent lead $\ce{PbL2}$ ($\ce{L}$ is ligand) reacts with something (again not sure, as I dont know the article) and what it reacts with gains a ligand. In less ...
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Make pure phthalocyanines from phthalocyanine dyes

We need a pure copper phthalocyanine for our experiments. Of course, we can buy it from Sigma Aldrich, but this means we'll have to wait a while. In local area we can buy only dyes which are about 98% ...
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What does unactivated, activated and deactivated aryl chloride means in cross-coupling reactions?

When I read this literature https://pubs.acs.org/doi/pdf/10.1021/jo990408i, it used unactivated aryl chloride for Buchwald-Hartwig amination. What does unactivated, activated and deactivated aryl ...
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CO stretching frequency band in the IR spectrum for tetracarbonylnickel and tetracarbonylferrate(II)

A past exam question says: With reference to the main bonding interactions between a transition metal and a terminal $\ce{CO}$ ligand, explain whether you would expect to observe a lower $\ce{...
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951 views

Why do heavy metals like mercury and lead have an affinity for sulfur or sulfur compounds?

Many of the heavy metals such as mercury, lead, thallium, cadmium, and arsenic exert toxic effects largely by binding to or otherwise interfering with organic sulfur compounds or groups in the body. ...
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How would the relative rate of reduction of carboxylic acid be if the catalyst used is LiAlH3D?

How would the relative rate of reduction of carboxylic acid be if the catalyst used is LiAlH3D , LiAlH2D2 , LiAlHD3 , LiAlD4 just thought about it while revising the reaction mechanism of carboxylic ...
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370 views

Comparing IR stretching bands in molybdenum complexes

Why would the infrared stretching frequency of $\ce{CO}$ (which is about $2140~\mathrm{cm^{-1}}$ in gaseous form) be $1982~\mathrm{cm^{-1}}$ in $\ce{[Mo(CO)_6]}$ and even lower in $\ce{[Mo(CO)3(η^6$\...
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Synthetic ferritin models and μ notation

This is the question verbatim: Details of two synthetic models of ferritin are presented below: System 1 $$\begin{multline}\ce{Fe(OAc)2 + LiOMe ->T[in presence of $\ce{O2}$][in MeOH]\\ ...
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I'm not sure I understand the stoichiometry of this mechanism

I was going through the experimental mechanism of nickelocene synthesis, and I looked through the notes and it said that there would be $\frac12$ $\ce{NiCl2}$. I'm sort of confused by the $\frac12$. ...
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Palladium catalyst

Recently I found the following question by sam: I'm supposed to produce dry and pure oxygen using the decomposition of hydrogen peroxide with a manganese dioxide catalyst. $$\ce{2H2O2(aq) -> ...
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Wilkinson's catalyst: why this structure?

I wonder how the structure of Wilkinson's catalyst contributes to its catalytic properties. For example, what role do the phosphine ligands play? What properties make Rh the best TM centre? Thank ...
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357 views

What happens to the Lithium halide salt when reacting Lithium metal with alkyl halides?

In organic chemistry, I learned a lot of useful reactions but unfortunately I didn't get to try many of them first hand (what's sad is I am a Chemistry major too). I've searched the internet back and ...