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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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40 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
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1answer
132 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 ...
2
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1answer
362 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
77 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, ...
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0answers
86 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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114 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 ...
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0answers
20 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
68 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
53 views

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
38 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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57 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?
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1answer
120 views

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 ...
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1answer
2k 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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0answers
53 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
400 views

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 ...
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2answers
319 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
78 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
93 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:...
3
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0answers
315 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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51 views

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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1answer
388 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
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.
3
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1answer
105 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
137 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
54 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
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1answer
282 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
330 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
811 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 ...
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1answer
85 views

How to reconcile conflict between assumed oxidation state and the most stable multiplicity from electronic structure calculations?

Consider either of the small, neutral molecules containing two Zn atoms below. If I were to determine the oxidation state of Zn from this molecule, I would formally assume each Zn to be Zn(I) in order ...
3
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2answers
440 views

Which complex is the most stable?

Between $\ce{[Rh(Ph2PCH2PPh2)3]^{3+}}$ and $\ce{[Rh(Ph2PCH2CH2PPh2)3]^{3+}}$, which one is the most stable thermodynamically? I think it's about the size of the chelate ring effecting their stability, ...
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1answer
141 views

Ketone/aldehyde synthesis from N-acylazetidines or aziridines

A common principle in organic chemistry is to make sure the product is less reactive than the starting material, to prevent overreaction. So, for example, the treatment of an ester with a Grignard ...
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1answer
464 views

Chemical function of Mg and Conjugated bonds in Chlorophyll [closed]

This question has 3 parts, each related to the title. In biochem, we were shown the chemical structure of chlorophyll. The light-absorbing head has many carbon-rings with alternating single and ...
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1answer
2k views

What's the explanation for the chelate effect? [duplicate]

I got that multidentate ligands form more stable coordination complexes than monodentate ligands, but why?
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0answers
34 views

Complexation of hydroxy chalcone oxime with metal [closed]

Does the complexation of 2-hydroxy chalcone oxime (below) with a metal require any catalyst? Is the complexation pH sensitive?
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1answer
126 views

What is the systematic name of ammonium bisoxalato cuprate (II)? [closed]

What is the systematic name of ammonium bisoxalato cuprate(II)? I already tried $\ce{(NH4)2[Cu(C2O4)2]^{2+}}$ but i am uncertain if that answer is correct.
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1answer
491 views

How are Grignard reagents stable in an ethereal solution? [duplicate]

I have heard of the leveling effect, which mentions that highly basic ions cannot exist in a solvent if it's acidity is high enough to be deprotonated by the base. Considering that, check out the ...
2
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1answer
177 views

Why does a smaller bandgap correlate to increased absorption of visible light?

I am currently involved in a project on metal organic frameworks in my AP chemistry class, and specifically their applications in $\ce{CO2}$ reduction into formate. All the explanations we can find on ...
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2answers
74 views

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 ...
8
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2answers
742 views

Is the term “heteroatom” reserved for exclusive elements?

From my experience, typically in organic chemistry, the implication of "hetero-atom" in some molecule is understood as B, N, O, S, P or a halogen -- or any nonmetallic element, perhaps. If one ...
13
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1answer
394 views

Noyori hydrogenation and the Curtin–Hammett principle

My question is relating to how the Curtin–Hammett principle applies to homogeneous hydrogenation using chiral ligands. Figure 0: An example of a quadrant diagram used as a mnemonic to predict the ...
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0answers
744 views

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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1answer
225 views

Terminal Alkyne in Suzuki Coupling

I've done a very similar reaction to the one below but by TLC I observe only starting materials. It's super clear that nothing else is going on. Conditions: K3PO4, Pd(dppf)Cl2, dioxane/water, heat to ...
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0answers
733 views

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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58 views

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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0answers
946 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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154 views

Grignard Reagent R group [closed]

Can the R group of a Grignard reagent (RMgX) be an alkene? Also what groups can't R be?
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1answer
839 views

Does 30% hydrogen peroxide eat away at platinum?

if I soaked a platinum dish with 30% hydrogen peroxide, will it eventually eat away at it?
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116 views

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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1answer
6k views

Why can't the reaction of grignard reagent with carboxylic acid give a ketone?

I understand that a Grignard reagent can act both as a base and a nucleophile. It acts as a base in the presence of a proton source (eg: alcohols, amine, water, etc). But when reacting with a ketone ...
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0answers
99 views

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 ...