Are There Dative Bonds In Isocyanides ?

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Discussion Overview

The discussion revolves around the representation of isocyanides and HNC (hydrogen isocyanide) in chemical structures, specifically the use of dative (coordinate) bonds versus triple bonds with charges. Participants explore the validity and prevalence of these representations in various educational contexts, particularly in Indian publications.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants question the correctness of representing HNC and isocyanides with a dative bond, noting that many sources do not support this structure and instead describe a triple bond with charges.
  • One participant suggests that the structure can be viewed as a resonance hybrid, where nitrogen's lone pair can form a bond with an empty orbital on carbon, leading to a triple bond with formal charges.
  • Another participant acknowledges that while a dative bond can be used, it is not a common representation, expressing concern about potential confusion arising from this approach.
  • Some participants note that isocyanides are known to form dative bonds with metal centers, indicating a different context for the use of dative bonds.
  • There is mention of other functional groups, such as the nitro group, being represented similarly with dative bonds in certain contexts, suggesting a trend in specific educational materials.
  • One participant points out that the representation of ammonia-boron trifluoride can also vary, illustrating a broader pattern in how dative bonds are depicted in chemical structures.

Areas of Agreement / Disagreement

Participants express differing views on the appropriateness of using dative bonds for isocyanides and HNC, with no consensus reached on the validity of this representation. Some acknowledge its use while others find it uncommon or confusing.

Contextual Notes

Participants highlight that the representation of dative bonds may be influenced by regional educational practices, particularly in India, and that there may be a lack of clarity in how these structures are typically taught or represented in various sources.

Navin
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TL;DR
Can We represent Isocyanides (RNC) with a dative bond ?
Okay guys, i had a question. Now in many indian publications and lecture rooms they say that we can represent HNC and isocyanides with a dative(coordinate) bond, but when i looked it up online, almost no one used such a structure. Wikipedia, Quora, Chem libre texts, etc, they describe it having a triple bond with charges.

Uh is the dative structure even correct ? Or is it an error that has been persistent is a bunch of indian publications ?Sources
With Dative Bond
1)Mtg-Interactive Irganic Chemistry by Girijesh Dubey (pg 623)
2)Resonance KVPY-SX Stream : Chemistry
1571210566226716413443.jpg
 
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The structure can be represented as a resonance hybrid, as on the Wikipedia page:
1571222499839.png

The double-bonded form has a lone pair on nitrogen and an empty orbital on carbon (1 lone pair rather than 2). N can use its lone pair to bond with the empty C orbital to make a triple bond, then N has a formal positive charge and C a formal negative charge. (You can draw the third bond as dative with an arrow, but that is not usual.)
The triple-bonded structure can be considered as related conceptually to the cyanide by removing a proton (and a neutron, but we don't worry about that) from the N atom of the cyanide and adding it to the C atom. This produces an isoelectronic molecule, but with charges as shown. The charges are not always drawn, especially when we are not focussing on the bonding but just representing the compound (e.g. saying A reacts with B to give C).
 
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Ah, okay . So we can use a dative bond, but it aint a common format right ?

Also thank you for explaing the structure of the molecule, i have a tendency of getting confused with the nitrogen lone pair while solving reaction based questions, this helped clear some doubts about it
 
I admit, I've never seen an isocyanide drawn that way. It seems like a recipe for confusion, especially because isocyanides themselves are really good at forming dative bonds with metal centers (as @mjc123 's vinyl carbene resonance structure suggests).
 
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TeethWhitener said:
I admit, I've never seen an isocyanide drawn that way. It seems like a recipe for confusion, especially because isocyanides themselves are really good at forming dative bonds with metal centers (as @mjc123 's vinyl carbene resonance structure suggests).
Oh and that's not all

We represent the Nitro group(-NO2) the same way too, istead of showing charges, we show one dative bond with one oxygen and a double bond for the other

There were some other compounds too, i can't recollect though. Basically all those compunds with formal charges were represented with dative bonds. I guess its an Indian thingie
 
It seems to be a general thing, e.g. ammonia-boron trifluoride may be drawn as
H3N→BF3
or H3N+-B-F3
 
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