Comments on: How Do We Know Methane (CH4) Is Tetrahedral?

By: James Ashenhurst

James Ashenhurst — Tue, 19 Dec 2023 12:32:17 +0000

In reply to Anonymous. Thank you for the helpful comment!

By: Anonymous

Anonymous — Wed, 13 Dec 2023 20:39:31 +0000

Just a small nitpicking point: I believe that in the first (incorrect) model of methane with the 3 “p orbital bonds” along the x, y, z axes, in order to minimize repulsion the remaining “s orbital bond” should really be pointing in the (-1, -1, -1) direction as opposed to the (-1, -1, 0) direction, in which case the H-C-H bond angle would actually be about 125.3 degrees, or 180 degrees minus the magic angle: https://en.wikipedia.org/wiki/Magic_angle.

By: Staggered vs Eclipsed Conformations of Ethane | Straight A Mindset

Staggered vs Eclipsed Conformations of Ethane | Straight A Mindset — Thu, 07 Dec 2023 21:51:35 +0000

[…] a previous post we discussed how we know that methane CH4 is tetrahedral (See: How Do We Know That Methane Is Tetrahedral), as this shape maximizes the distance between the repulsive bonding electron […]

By: How Do We Know Methane (CH4) Is Tetrahedral? | Straight A Mindset

How Do We Know Methane (CH4) Is Tetrahedral? | Straight A Mindset — Tue, 17 Oct 2023 22:36:47 +0000

[…] We would therefore expect to observe a small, but measurable dipole moment for CH4. [Note 1] […]

By: Orbital Hibrida dan Hibridisasi – Belajar Kimia

Orbital Hibrida dan Hibridisasi – Belajar Kimia — Wed, 15 Feb 2023 04:28:36 +0000

[…] In the last post on the structure of methane we asked how we know that methane is tetrahedral (See Article: How Do We Know That Methane Is Tetrahedral). […]

By: James Ashenhurst

James Ashenhurst — Wed, 26 Jan 2022 04:04:20 +0000

In reply to F. E. Ziegler. Thank you very much. I have benefitted from your site for years.

By: F. E. Ziegler

F. E. Ziegler — Fri, 07 Jan 2022 15:27:23 +0000

See a Brief History of Organic Chemistry here (slides 35 and 36): http://ursula.chem.yale.edu/~chem220/chem220js/StudyAids.html#History
If memory serves me correctly, A. W. Hofmann was giving this lecture about the time that Lee was surrendering to Grant in 1865.

By: Staggered vs Eclipsed Conformations of Ethane - Eazy Info

Staggered vs Eclipsed Conformations of Ethane - Eazy Info — Mon, 27 Dec 2021 11:44:23 +0000

By: James Ashenhurst

James Ashenhurst — Mon, 01 Jul 2019 12:16:23 +0000

In reply to Rafael. This is a very good point. A square planar carbon with 4 different substituents can actually have *three* isomers (try it), all stereoisomers but none of them enantiomers.

By: Rafael

Rafael — Fri, 21 Jun 2019 23:18:29 +0000

I believe that the idea of a square planar carbon with 4 different substiuents having only one isomer is not accurate. Yes, the mirror image is the same as the original, but switching two substituents would provide a different isomer.
A square planar geometry, however, would make dichloromethane and similar molecules exist as 2 isomers (cis and trans), and would also increase the number of possible isomers for molecules with more than 1 stereochemical centers, breaking the 2^n rule.
As a sidenote, I want to say that I’ve been using this website since 2014 and I think it’s amazing, so thank you for the dedication.