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I propose that Methylene bridge be merged into Methylene group. I think that the content in the Methylene bridge article can easily be explained in the context of Methylene group, and the Methylene group article is of a reasonable size that the merging of Methylene bridge will not cause any problems as far as article size or undue weight is concerned. These two pages are on related subjects that have a large overlap, there does not need to be a separate entry for every concept. Plasmic Physics (talk) 01:43, 16 September 2013 (UTC)
Strongly support. There is a distinct phrase such as this, but the article does not clearly or solely address it. E.g., norbornane (bicyclo[2.2.1]heptane) has a methylene bridge, per se. This more focused concept can easily be subsumed as a section into the "methylene" article.
And as insinuated, I would also strongly suggest dropping the word "group". While -CH2- and -CH<, are technically groups, practicing organic chemists more or less unconsciously separate methylene and methine as structural elements in the carbon frameworks of organic molecules, and think of them distinctively from "groups" (much as they do not so much think of single heterocyclic atoms replacing carbons in a framework as a "group").
"Group", with its suggested inherent plural, is (again, likely unconsciously) reserved for substituents composed of literal groups of atoms that can be tethered onto the framework (carboxyl, nitro, alkyl, etc.), though in a pinch they might be extended to monovalent (single atom, terminal) substituents such as halides. (This, however, is formally incorrect, however common it might be: the suffix "-ide" is reserved for species generate through the loss of a proton, hence bromide from HBr, chloride from HCl, cyclopenta-2,4-dien-1-ide from cyclopenta-2,4-diene, etc. (search "-ide" here, ); hence, one would say "bromine atom" or "bromine substituent" before "bromide group".)
These are perhaps subtleties of professional language and practice that are not of highest importance, but since the change is taking place, it may as well be done in a way that sounds right to the best trained ears (and is shorter in links, to boot). that is, when learning a language, better to learn it without too strong of an accent (and so belie one's foreign origin, if possible). Le Prof Leprof 7272 (talk) 15:18, 29 May 2014 (UTC)
Do you mean that it can be subsumed into Methylene (compound)? A valid proposal, but one for another day. Let us first focus on merging these two articles, before deciding on a new name. Besides, the merged article cannot be called just Methylene, as that article name has already been taken up by the disambiguation page.
From what I understand, we have consensus on the merge. Thank you for contributing to this discussion, despite its age. Since we've received no opposition contribution, do you suppose we close it, or do we wait? Plasmic Physics (talk) 23:51, 29 May 2014 (UTC)
Slightly opposed: If you ignore that that the word 'methylene' is used in both - one's a terminal alkene, one's a bridging alkane. To my mind there's not lot of overlap there; in a complete molecule you'd never point and say that one was a structural isomer of the other, CH2 groups are abound. Their chemistry as functional groups is also going to be very different. I'm just not seeing a connection here, other than the name. On a side note, these pages were originally part of Methylene (compound) and were split off in January 2013, largely to allow that page to focus in radical chemistry. Project Osprey (talk) 12:14, 1 June 2014 (UTC)
I see no reason why the difference could not be addressed in a merged article. The two groups aren't structural isomers, they are essentially the same group, only with different attaching motifs. Concerning you side note, there is no strong connection between the groups and the radical, other than the name. Groups and radicals are apples and oranges, terminal and bridged forms of a group are Valencia and Hamlin oranges. Plasmic Physics (talk) 12:41, 1 June 2014 (UTC)
I respectfully disagree with Plasmic Physics on their last point. A methanediyl (methylene bridge) is centered on an sp3 hybridized carbon, whereas a "methylene group" has an sp2 hybridized carbon, and has a filled pi molecular orbital, which contribute to significantly different chemical properties of these moieties. -220.127.116.11 (talk) 22:22, 14 August 2015 (UTC)