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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questions
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Reaction mechanism of lithiated benzene and oxygen in acid
According to (1) addition of O2 in acid to lithiated benzene makes phenol.
I'm trying to deduce the mechanism, and somehow it doesn't feel right but I'm not sure.
(1) Snieckus, V. Directed ortho ...
3
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1answer
66 views
What is the mechanism of this reaction?
I've been stuck with this for some time. I just don't see it. As the reactant is Pd(0), I think oxidative addition will happen to the bromine. Then I would say an insertion reaction happens. However ...
1
vote
1answer
51 views
Triphenylphosphine (PPh3) vs. 1,2-bis(diphenylphosphino)ethane (dppe) ligand?
What about $\ce{NiCl2(dppe)}$ makes it a more efficient catalyst for Suzuki cross-coupling as opposed to $\ce{NiCl2(PPh3)2}$ or $\ce{NiCl2(PCy3)2}$? How does the dppe ligand increase the reactivity of ...
0
votes
1answer
72 views
What is the oxidation state of copper in Gilman's Reagent? [closed]
What is the oxidation state of copper in Gilman's reagent? In $\ce{R-Cu}$ bond the oxidation state is +1. Thus in $\ce{R-Cu-R}$ bond the oxidation state has to be +2. But if that so why positive $\ce{...
6
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1answer
189 views
Volatile alkali metal compounds
Most elements are or have compounds that are gases or have a significant vapor pressure at room temperature. Fluoride is a powerful tool for producing highly oxidized covalent and volatile compounds. ...
2
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49 views
How does electrophilic bromination with 1,2-dibromoethane work?
Hi I am trying to figure out the mechanism of a reaction containing a lithium carbanion and 1,2-dibromoethane in THF. The lithium carbanion is generated by deprotonating using LDA. Then 1,2-...
0
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0answers
32 views
Why do statistical effects impact stepwise stability constants?
I have a question regarding the stepwise stability constants of metal complex formation/substitution.
My lecture notes say that if we have a metal complex, say $\ce{[MX_{6}]}$, and a substitution ...
1
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0answers
33 views
Why CO is a weak pi-acid ligand?
This question was given by my chemistry professor, but I doubt that this question is not correct.
Following the lewis definition of the acid, any molecule or atom acts as a acid if it accepts an ...
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38 views
Organometallic Synthesis: Cp2Ti(I)Me from TiCl4
I've been working on this synthesis question for a couple days but I'm a little stuck. The question is:
Using only $\ce{TiCl_{4}}$, $\ce{NaCp}$, $\ce{PhLi}$, $\ce{MeI}$, and $\ce{EtMgBr}$, ...
1
vote
1answer
61 views
Why does cyclobutadieneiron tricarbonyl behave aromatically?
It is said that $\ce{(\eta^4-C4H4)Fe(CO)3}$ can undergo electrophilic substitution reactions. Therefore, it displays aromaticity.
For the iron atom, it has $8$ electrons in its outer shell initially ...
3
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0answers
32 views
IRC analogue of conical intersections and minimum energy crossing points?
In my project, there are some spin forbidden organometallic reactions that involves both the triplet minima and singlet transition state (TS). Using the penalty method in qchem as well the method of ...
2
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1answer
92 views
Why there are more examples of carbonylate anions than metal carbonyl cations?
I know that metal carbonyl complexes that do not follow EAN rule or 18 electron rule try to achieve that by gaining electron (forming carbonylate) or loosing electron (forming carbonyl cations). But ...
0
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1answer
66 views
Why has nature evolved to put a porphyrin (i.e. chlorophyll) as the chromophore in a leaf? [closed]
I'm stumped by this question:
Why has nature evolved to put a porphyrin (i.e. chlorophyll) as the chromophore in a leaf?
I've thought that it might have something to do with how sun emits light ...
4
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0answers
26 views
Further reading on photoconductivity of hemoglobin
I recently ran into this paper which describe experiments that confirm that hemoglobin is photoconductive. Finding this fact as incredible, I wanted to read up more on photoconductive properties of ...
2
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0answers
43 views
Why doesn't Grignard reagent attack alkyl halides [duplicate]
When we add magnesium to
alkyl halide, Grignard reagent is formed. $$\ce{R-X + Mg -> RMgX } $$ It is highly nucleophilic in nature. Now at this time the electrophilic alkyl halide is also present ...
2
votes
1answer
120 views
How does 1-bromo-2-fluorobenzene react with lithium amalgam? [closed]
How does this organometallic reagent react with 1-bromo-2-fluorobenzene? Does it react like Grignard reagent? If the product of this reaction is then reacted with furan, what will be the final product?...
3
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On the stability of methyl mercury
Question: Given that $\ce{Zn, Hg}$ are in the same group, how to explain that $\ce{Hg(CH3)}$ is stable but $\ce{Zn(CH3)}$ is unstable and $\ce{Hg(CH3)Cl}$ is stable? $\ce{Hg(CH3)}$ seems to have an ...
3
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1answer
291 views
Will ferrocene undergo electrophilic aromatic substitution?
Ferrocene has two structure 1 and 2.It is bonded to an aromatic ion cyclopentadienyl anion.Aromatic species such as benzene , cyclopentadienyl anion undergo electrophilic aromtic substitutions.
Then,...
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25 views
Alkyl insertion with cobalt and CO
Reaction of $\ce{(Cp)Co(Me)2(CO)}$ in the presence of excess $\ce{CO}$ yields two different organic products, $\ce{A}$ and $\ce{B}.$ The only metal-containing product is $\ce{(Cp)Co(CO)2}.$ The IR ...
2
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0answers
20 views
Will lead bind to dissolved polymer (Kapton) monomers?
We are attempting to determine the concentration of lead impurities in Kapton. Essentially we need to extract lead in the tape polymer Kapton (structure seen below);
The amount of lead in the tape is ...
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34 views
Electron-donating trends for ligands bound to metal complexes
Imagine an inorganic complex with a bunch of terminal ligands. All else the same, would $\ce{F-}$ or $\ce{Br-}$ ligands be more electron-donating and why?
Of course, in terms of $\mathrm{p}K_{\mathrm{...
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109 views
Can pi backdonation occur on non-metal centers?
The common example of back-donation is the interaction of a CO molecule with a metal center (d-orbitals) on a surface.
Can a similar mechanism occur between CO and a non-metal center, like oxygen on ...
2
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1answer
69 views
N-heterocyclic carbene metal complexes. Question about the delocalization of the nitrogen lone pairs
I am wondering why nitrogen lone pairs are delocalized in NHC metal complexes. What I can think of is, when complex is formed, plus charge is formed on the carbon atom and therefore delocalization ...
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1answer
441 views
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 ...
4
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1answer
2k views
Grignard Reagent in THF vs in Diethyl ether
While learning about the Grignard reagent I was taught this by my teacher, but I couldn’t justify why it was so..
I cannot see how Grignard reagent would react differently in basically an ethereal ...
2
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1answer
104 views
Is an alcohol-based spray cleaner ok for cleaning an aluminum heat exchanger?
Simple alcohols such as ethanol can, apparently, corrode aluminum. However, this corrosion reaction seems to be very slow at room temperature and below. Is an ethanol based, non-foaming spray cleaner, ...
2
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0answers
320 views
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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290 views
Reaction of grignard with beta Keto ester [closed]
A reaction takes place between $\ce {CH3COCH2COOC2H5}$ with 4-chlorophenyl magnesium bromide, followed by acidic work-up. What will be major product of the reaction? Would the product be the same as ...
2
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0answers
27 views
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 ...
2
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0answers
240 views
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 ...
4
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1answer
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Is it possible to have a ferrocenol?
I'm specifically talking about having a hydroxy- group on the ferrocene ring.
Is it simply impossible because the ring is anionic?
I haven't seen any hydroxyferrocene molecules available online. (...
2
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1answer
42 views
How do we know cyclopentadienylmolybdenum tricarbonyl occurs as a dimer?
Cyclopentadienylmolybdenum tricarbonyl, $\ce{MoC8H5O3}$, dimerizes to form the cyclopentadienylmolybednum tricarbonyl dimer, $\ce{(MoC8H5O3)2}$.
$\hspace{3cm}$
How was it discovered that it does ...
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0answers
87 views
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?
10
votes
1answer
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How can the solid state structure of cyclopentadienyllithium be explained?
In the solid state, LiCp adopts a polymeric multidecker structure where Li atoms are sandwiched between two Cp rings (shown in this diagram from Organometallics 1997, 16 (17), 3855–3858):
If we ...
3
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1answer
4k views
How to electron count bridging ligands?
Although I am okay with rationalising bridging halides and $\mu$-2 CO I can't seem to figure out others, including $\mu$-2 hydride, CN- and NO.
When considering the electron count of bridging ligands,...
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89 views
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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1answer
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Mechanism of lithium-halogen exchange of primary alkyl iodide
On Clayden's page 190 this reaction is given for preparation of organometallics:
What is the mechanism of this reaction? I expected the "almost carboanion" part of the $\ce{t-BuLi}$ to attack as a ...
4
votes
2answers
459 views
How does the Wurtz reaction produce alkynes?
Wikipedia mentions that alkynes can be produced from geminal dihalides through the Wurtz reaction. However, I am unsure of the reaction mechanism for this reaction. I have not been able to find any ...
2
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1answer
85 views
What is the product of magnesium reacting with carbon?
$$\ce{Mg + C -> X}$$
$$\ce{X + H2O -> Y}$$
Determine unknowns X and Y.
Now the problem is I think the answer should be $\ce{X=MgC2}$ and $ \ce{Y=C2H2 + Mg(OH)2}$. But the given answer was ...
2
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1answer
118 views
One-pot synthesis of pyrazole [closed]
I am trying to follow a published paper. It is a one-pot synthesis of pyrazole from a ketone and and acid chloride via a diketone intermediate.
Here is the produre from the paper:
General Procedure:...
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0answers
559 views
Mechanism for reaction of an allene with the Grignard Reagent(RMgX)
How does the Grignard Reagent($\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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How can organocuprates generated with catalytic Cu(I) be competitive in 1,4-addition to an enone?
Organocopper 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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1answer
569 views
Why are 3 equivalents of organolithium needed in synthesis of ketone from carboxylic acid?
For the reaction of a carboxylic acid and organolithium reagents to synthesise a ketone, Clayden's, on p 219, mentions:
Notice that three equivalents of organolithium are needed in this reaction: ...
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1answer
357 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.
3
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1answer
120 views
Is associative ligand exchange possible with octahedral complexes?
Can associative ligand exchange produce an octahedral intermediate as long as the initial complex has 16 electrons (unsaturated)?
Not sure. all I ever see is a square planar turning into a trigonal ...
14
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2answers
149 views
Mechanism of a Gold catalyzed organometallic reaction: Confusion regarding the last step
I needed to draw the reaction mechanism for this reaction:
So, after consulting some literature I drew this mechanism:
But, I am not sure about the last step. Does the $\ce{H+}$ just substitute the $...
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0answers
70 views
Looking for a low boiling point solvent for MAPI precursors (Lead Iodide (II) and Methylammonium Iodide) [closed]
Things I have thought of till now:
Acetonitrile with HI additive
Acetonitrile with DMSO additive
The problem with the first would be that HI is in an around 55% aqueous solution and water doesn't ...
17
votes
1answer
411 views
How to name this quintuply-bonded chromium dimer?
Depicted below is a chromium compound with a metal–metal quintuple bond. It boasts two identical bridging ligands, derivatives of 1,3-diphenylbenzene. The aim of this question is to figure out
the ...
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0answers
494 views
C-O bond strength in metal carbonyls [duplicate]
The metal carbonyls (and similar organometallic compounds) involve a combination of a $\sigma$-bond, a $\pi$-bond and backbonding. The bond strengths under consideration are the metal-carbon bond and ...
14
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1answer
864 views
Are there any significant uses of the compound formed by magnesium and anthracene?
In an unusual reaction, magnesium reacts with anthracene in THF to form a grignard-like compound called, prosaically, magnesium anthracene:
I remember using it briefly in the 1980s. At the time there ...
