Tetra diborates

C24H55B2N, Tetra-n-butylammonium M hydro-1,2-dihydro-1,2 1,2-bis-(tetramethylene)diborate, 41B, 709... 

Noth El, Knizek J, Ponikwar W (1999) A boron-boron double bond in the dianions of tetra (amino)diborates. Eur J Inorg Chem 1999 1931-1937... 

In order to test this hypothesis and determine an appropriate structural model for solution-deriyed lithium borate networks (gels), Brinker et al. performed FTIR investigations of crystalline alkali borates and partially hydrated crystalline alkali-borates (with N4 = 0.25 to 0.50). A prominent spectral feature (see, e.g.. Fig. 37a) of the anhydrous tetra- and triborate compounds is the 1260-cm vibration due to oxygens bridging between trigonal borons contained in separate primary units [183] (Fig. 38a). Anhydrous lithium diborate is composed exclusively of diborate units linked by oxygens bridging between 3- and 4-coordinated borons and exhibits no 1260-cm vibration [185]. Partial hydrolysis of the tetra- (and triborates) causes a dramatic reduction in the relative intensity of the 1260-cm vibration (Fig. 37b). 

The same authors exhibited a comparative study on the activation of (MeO)2B-B(OMe)2 and (Me2N)2B-B(NMe2)2 vtith the platinum(O) complex [Pt(PPh3)4], and further application to the diboration of 1-octyne. The results clearly demonstrated that both the tetra(alkoxy) diboron performed in a similar way (quantitative conversion on the a s-l,2-diborated product, under 80 °C), but the tetrakis(dimethylamino) diboron was only added in 7% to the 1-octyne, even at 120 The oxidative addition of... 

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