Talk:Quadruple bond

Early Soviet work - source needed to know what they did

The unsourced statement in this article about unnamed researchers in the USSR says that they characterized K₂Re₂Cl₈ as having a quadruple bond prior to Cotton. However the article on Potassium octachlorodirhenate says that although Soviet chemists reported the compound in 1954, it was Cotton and Harris in 1964 who discovered the short Re-Re bond (and the eclipsed geometry?). Since the bond length and the geometry is usually quoted as the evidence for the bonding scheme, presumably the Soviet researchers just based their conclusion on electron counting. Or did they in fact refer to a quadruple bond at all? Could we have a source for this work please? Dirac66 (talk) 03:55, 23 February 2014 (UTC)[reply]

Fair point. I am partly responsible for some of these claims. [Re₂Cl₈]^2- is featured on an 1968 soviet postage stamp, so they have a stake. My recollection is that they solved the structure but assigned it to two closely spaced sq planar [ReCl₄]^- species and Cotton is the one to propose the quadruple bond. Remind me if I dont get on this. --Smokefoot (talk) 04:16, 23 February 2014 (UTC)[reply]

Thanks. I think the place for mentioning who synthesized the compound is in the article on the compound rather than this article. So assuming your recollection is accurate, we probably should remove mention of the Soviets from this article and just give them credit in the other article. This would be analogous to acetylene, which was the first example of a carbon-carbon triple bond. The discovery (and re-discovery) of acetylene are considered in the article Acetylene, not in the article Triple bond. Dirac66 (talk) 01:34, 24 February 2014 (UTC)[reply]

The History section was now one long paragraph in which the Soviet work was described but without mentioning the Soviets. This left it unclear to whom These researchers referred. A historically ignorant reader might even have read the section to say that Peligot used crystallography in 1845:-))).

To clarify who did what, I have divided the section into 3 short paragraphs, one for each research group. I have also restored the mention of the Soviet chemists to specify whom we are talking about (at least by nationality), but added a citation needed tag for this claim. Dirac66 (talk) 23:07, 29 May 2016 (UTC)[reply]

Russian literature

Kuznetsov, V. G.; Koz'min, P. A. "The structure of (pyH)HReCl4" Zhurnal Strukturnoi Khimii 1963, 4, 55-62. Excerpts from abstract: "The cryst. structure of the pyridine deriv. of the tetrachloride of bivalent Re, (pyH)HReCl4 was detd.... space group is D192h-Cmmm. The basic structure seems to consist of dimeric ions [Re2Cl8]2- exhibiting the form of a square prism in which, besides the 4 covalent bonds Re-( 1 of 2.43 kX length, the bond Re-Re of 2.22 kX length exists,..." This paper first describes Re₂Cl₈^4-. There are earlier reports but I dont think that they have structures. Even in this one, they erred in invoking both pyridinium and H⁺ as countercations. More later (obviously moving at a slow pace!). According to Cotton, the Russians were fixated on Re(II) vs what turned out to be Re(III). They celebrated their achievement with a postage stamp as seen here: https://books.google.com/books?id=mybpaEKibKsC&pg=PA135&lpg=PA135&dq=stamp+Re2Cl8&source=bl&ots=BTOG8kAwhE&sig=ArBZPWCMwo5WmI-VEpudV1WWJX8&hl=en&sa=X&ved=0ahUKEwiEwevTpI_NAhVRLVIKHc95CNIQ6AEIJzAA#v=onepage&q=stamp%20Re2Cl8&f=false--Smokefoot (talk) 21:10, 4 June 2016 (UTC)[reply]

Very good. I have inserted the Kuznetsov-Koz'min paper as a source for the mention of the Soviet work in the article. Can you also find a DOI which will enable Wikipedia readers to click on the English abstract that you have quoted? Dirac66 (talk) 23:05, 4 June 2016 (UTC)[reply]

Two comments. CAS told me that there is no DOI for this paper. Apparently DOIs for older literature are assigned/recommended by the publishing houses. Second comment, the Russians showed that the bond was super short as quoted above. Cotton, I think, is the one who explained the quad bonding mode with d-orbital overlap. --Smokefoot (talk) 00:26, 21 June 2016 (UTC)[reply]