Please don't say sodium tetraborate decahydrate since that is not the real composition of borax.
Borax contains tetranuclear coordination complexes $\ce{[B4O5(OH)4]^-^2}$. I'm asking about the name of this complex in borax.
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13$\begingroup$ Sodium tetraborate decahydrate is a legitimate IUPAC name. If you want to impress a girl, use sodium bicyclo[3.3.1]tetraboroxane-3,7-diolate hydrate (2:1:10), or pick further German/French names from here. $\endgroup$– andselisk ♦Commented Jul 25, 2017 at 10:34
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2$\begingroup$ This might help you-chemistry.stackexchange.com/questions/59273/structure-of-borax $\endgroup$– Nilay GhoshCommented Jul 25, 2017 at 14:41
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1 Answer
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The name suggested here (via the question comments), the anion-corresponding part, ‘bicyclo[3.3.1]tetraboroxane-3,7-diolate’ ($\ce{[B4O5(O)2]^2-}$) obviously does not match with the tetraborate formula $\ce{[B4O5(OH)4]^2-}$ present in borax, whose structure, confirmed by X-ray crystallography, including hydrogens[1], is
However, the ‘bicyclo[3.3.1]tetraboroxane’ part is correct, for the parent hydride:
This type of names is known e.g. for the ‘cyclotriboroxane’ name for boroxine, or ‘cyclotetrasiloxane’ (in octamethylcyclotetrasiloxane).
So the name would be rather 1,3,5,7-tetrahydroxybicyclo[3.3.1]tetraboroxane, or bicyclo[3.3.1]tetraboroxane-1,3,5,7-tetrol, however it still does not explicitly tell that it's an anion.
Interestingly, this boroxane, siloxane type names (interchanging element/oxygen pattern) is rather marginally mentioned in the inorganic nomenclature, notably more detailed in the organic nomenclature.[2]
Inorganic additive nomenclature is able to constructs names for similar skeletons,[3] but somewhat differently than organic nomenclature.
E.g. bicyclo[x.y.z]Nane (where N is the numerical prefix root, with the exception for 1..4, ‘meth’..‘but’, for the organic names) would be named: Ncarby-[0a.z1,b]dicycle, where a = x+y+2 and b = x+2. If the structure is an ion, it's ‘…cyclate’ followed by the charge in parentheses. One advantage is that the first numeral is the size of the (largest) cycle, not just a branch.
Some examples from the book:
1,7-diazyundecasulfy-[012.11,7]dicycle
(IR-1.5.3.4 Example 6)
cyclo-triphosporic acid
2,4,6-trihydroxido-2,4,6-trioxido-1,3,5-trioxy-2,4,6-triphosphy-[6]cycle
(IR-8.3 Example 5)
tetraaluminy-1-lithy-[05.01,301,402,5]tetracyclate(1−)
(IR-7.4.3 Example 11)
(The leading zero in the first numeral in the square brackets is intentional for the cycles, however in the latter example, it's not used, despite IR-7.4.2 Nodal descriptor, example 3, that states that the nodal descriptor for hexacycle is ‘06’.)
With this nomenclature we can get very descriptive (but almost unusable) names
1,3,5,7-tetrahydroxido-1,3,5,7-tetrabory-2,4,6,8,9-pentaoxy-[08.11,5]dicyclate(2−),
1,3,5,7-tetrahydroxidotetrabory-2,4,6,8,9-pentaoxy-[08.11,5]dicyclate(2−), or
1,3,5,7-tetrahydroxido-1,3,5,7-tetraborypentaoxy-[08.11,5]dicyclate(2−).
References:
- Levy H.A., Lisensky G.C. Crystal structures of sodium sulfate decahydrate (Glauber's salt) and sodium tetraborate decahydrate (borax). Redetermination by neutron diffraction Acta Crystallographica Section B 34 (1978): p. 3507
- IUPAC Blue Book 2013, P-52.1.6.2
- IUPAC Red Book 2005, IR-7.4 Additive nomenclature: Inorganic chains and rings
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1$\begingroup$ snort dicyclate! :D Yep, that almost unusable, indeed... $\endgroup$– MithoronCommented Jun 3, 2020 at 15:35