Poly[di-mu2-methanolato-di-mu2-tetramethoxyborato-disodium(I)].

In the polymeric title compound, [Na2(C4H12BO4)2(CH4O)2]n, the two independent sodium cations are bound by five O atoms. All the O atoms of one tetramethoxyborate anion bind cations, forming a tetrameric cluster around a tetragonal inversion centre [Na-O = 2.2777 (18)-2.3907 (16) A]. Two methanol O atoms bridge the two Na atoms [Na-O = 2.3590 (15)-2.4088 (18) A] and provide the hydrogen-bonding H atoms. The second tetramethoxyborate anion provides two O atoms to one Na atom [mean Na-O = 2.31 (2) A] and two O atoms as donors for crosslinking hydrogen bonds to adjacent tetramers, which complete the three-dimensional packing. The crystal was a treated as a racemic twin.