Questions tagged [organometallic-compounds]
For questions relating to organic compounds which contain a bond between a carbon atom and a metal.
179
questions
3
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Reactivity of unsaturated organolithium compounds
I'm particularly looking in the context of alkyl lithiums compared to vinyl-lithiums and alkynyl-lithiums.
Why is it that shifting from sp3 to sp2, and even further to sp carbanions, reduces the ...
5
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0answers
25 views
Why transition metal catalyzed [2+2]cycloaddition reactions allowed?
As you know, cycloaddition reactions which (4n)π electrons are involved in such as [2+2]cycloaddition are forbidden in normal organic reactions, but transition metal catalyzed [2+2]cycloaddition ...
0
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0answers
17 views
Why does π-backbonding in a metal-carbonyl complex lead to a decrease in C-O bond strength?
I understand that π-backbonding in this complex involves the σ-donation of carbonyl to an empty d orbital of the metal, and the π-donation of the d electrons of the metal to the π* MO of the carbonyl. ...
0
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0answers
20 views
The role of PIDA in C-H activation reactions
PIDA ((Diacetoxyiodo)benzene) is a hypervalent iodine(III) compound that acts an attractive oxidizing agent in most of the transition metal catalyzed reactions. Can someone explain me the mechanism of ...
5
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0answers
30 views
Is it possible to do Cobalt catalyzed directing group asisted meta C-H functionalization of arenes
Directing Group assisted Pd catalyzed (sp2)meta-C-H functionalization has a growing attention in recent years.
In addition, few examples can be found for meta-C-H functionalization via Rhodium. I am ...
4
votes
1answer
101 views
Bridging Hydride Covalent Model Electron Count - Hartwig
How can a bridging hydride be considered a 3 electron donor in the covalent model for electron counting?
On page 3 of John Hartwig's "Organotransition metal chemistry" textbook [1], he lists ...
4
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0answers
26 views
Aluminium isopropoxide electronic structure
From Wikipedia:
A tetrameric structure of the crystalline material was verified by NMR spectroscopy and X-ray crystallography. The species is described by the formula $\ce{Al[(μ-O-i-Pr)2Al(O-i-Pr)2]3}...
4
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0answers
81 views
Nature of a1g Molecular Orbital Interactions in Ferrocene
While learning about ferrocene I've come across this molecular orbital diagram.
What particularly confused me is the nature of the a'1g orbital. My professor taught that a'1g and e2g are considered ...
1
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0answers
29 views
What is the proper use of the term “pi-donor ligand”?
Robert Crabtree's The Organometallic Chemistry of the Transition Metals (7e) describes a pi-donor ligand as being a pi-donor "as a result of the lone pairs that are left after one lone pair has ...
0
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1answer
102 views
Can copper sulfate react with terpenes (such as limonene and terpinenes) at room temperature?
I am just wondering, can I make a metalorganic or organometallic complex of copper and limonene/terpinene/phellandrene in the form of lime oil? If so, what is the formula of the complex formed? I ...
2
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0answers
46 views
Can someone help with the nomenclature of this metal complex. MarvinSketch is giving me trouble
I’m trying to get a name for the structure above using MarvinSketch for my undergraduate senior thesis. This is the first time I’ve had to draw a metal complex in MarvinSketch, and I’m having trouble ...
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votes
1answer
52 views
Weinreb ketone synthesis [closed]
For this problem, Can I use weinreb ketone synthesis? I found the product but not sure it is the right one
If the amide react with either R1-Mgbr or R2-Li,
then it produces the ketone?
3
votes
1answer
475 views
Wittig reaction in presence of carboxylic acids
The following reaction came in a recent test:
According to this reaction, the acidic hydrogen would protonate the ylide, and the standard wittig reaction would not take place. This source agrees with ...
4
votes
0answers
61 views
Metal coordination in enzymes: What type and number of bonds form between amino acid residues and Fe(II)?
My understanding: Transition (d-block) metals, as found in intracellular proteins, are limited to about 10 elements including amongst others Fe, Ni, and Cu. Due to the reductive environments inside ...
0
votes
1answer
91 views
Preparation of Grignard reagent. Free radical rearrangement
Mechanism of formation of Grignard Reagent
$$\ce{R-X + ^.Mg^. ->[\text{r.d.s.}] R^. + ^.Mg+X-} $$
$$\ce{R^. + ^.Mg+X- -> R-Mg+X-} $$
As the mechanism of preparation of Grignard reagent suggests,...
0
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0answers
57 views
In which condition CO uses the oxygen end for bonding?
Generally Metal Carbonyl complex are formed from Carbon end. Is it possible under some specific condition that the Oxygen end is used?
(PS -I know about the structures of M-CO bonding)
2
votes
1answer
87 views
What would be the product of following elimination reaction?
Question
Doubt
The answer is given B. But why cant it be C after all formation of cyclopropane would increase angle strain?
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0answers
223 views
How do you optimize an organo-metalic compound containing cerium in in Gaussian?
I am trying to perform optimisation of the molecule attached. I need to get partial charges and frequencies. The issue is that it doesn't converge with following input:
...
2
votes
0answers
58 views
What is the difference between a dπ-dπ and delta bond [closed]
I have always been wondering the difference between a dπ-dπ bond and a delta bond. What are the situations that either bond is formed in overlap of two d orbitals.
8
votes
1answer
200 views
Can ferrocene type sandwich compounds be made with fluorene?
Ferrocene will be well known to made members of this site. It consists of two cyclopentadienyl anions sandwiching an iron-II ion.
During my first year organic chemistry course (about 40 years ago) I ...
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votes
1answer
33 views
Reaction of grignard in presence of Halogen [closed]
What happens when a Ketone say $$RCOCH3$$ on reaction with grignard reagant in presence of X2 (halogen) what happens?? Can someone please explain
4
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0answers
40 views
Curtin-Hammett principle to evaluate alkene insertion
Given an unsymmetrical alkene in a simple non-stereoselective catalytic hydrogenation reaction. If one would want to investigate the nuances in the catalytic cycle of a dihydride complex leading to ...
2
votes
1answer
130 views
Reason for double acylation of ferrocene only occurring with certain reagent combinations
Can anyone explain why the acylation of ferrocene produces the following results:
Ferrocene + acetic anhydride + AlCl3 ==> mono-acylated ferrocene
but:
Ferrocene + acetyl chloride + AlCl3 ==> di-...
2
votes
0answers
31 views
Are there many examples of stable, well characterised organometallic compounds of saturated hydrocarbons with beta hydrogens?
One of the first things you tend to learn in organometallic chemistry is that transition metal compounds containing beta-hydrogens are unstable (there are plenty of stable main groups ones; eg ...
0
votes
1answer
72 views
Organometallic and oxygen
I often read that reactive organometallics must be handled under an inert atmosphere because they react with oxygen in the atmosphere. This applies to grignard reagents, organolithium reagents, and ...
2
votes
0answers
74 views
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
votes
1answer
127 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
229 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
486 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
votes
1answer
319 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
votes
0answers
205 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
40 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
vote
0answers
89 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 ...
1
vote
0answers
44 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
140 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
votes
0answers
47 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
votes
1answer
390 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
votes
1answer
88 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
votes
0answers
28 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
votes
0answers
71 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
439 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
votes
0answers
33 views
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
votes
1answer
965 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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0answers
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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
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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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0answers
43 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{...
12
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0answers
155 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
votes
1answer
310 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 ...
6
votes
1answer
1k 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
5k 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 ...
