Synthesis, Spectroscopic Studies and Crystal Structures of [Et 2 Sn(O 2 AsMe 2 ) 2 ] and [Ph 2 Sn(O 2 AsMe 2 )(μ‐OMe)] 2

[Et 2 Sn(O 2 AsMe 2 ) 2 ] ( 1 ) and [Ph 2 Sn(O 2 AsMe 2 )(μ‐OMe)] 2 ( 2 ) were synthesized by treatment of Et 2 SnO and Ph 2 SnS with HO 2 AsMe 2 in Methanol, respectively. The compounds were characterized by elemental analyses, vibrational spectroscopy and mass spectrometry. According to X‐ray diffraction measurements compound 1 crystallizes monoclinic in space group P 2 1 / n with cell parameters a = 804.89(3), b = 987.11(5), c = 966.42(4) pm, β = 113.354(3)°. The unit cell parameters of 2 , which crystallizes in the same space group, are a = 974.4(1), b = 1463.3(1), c = 1228.9(1) pm, β = 111.324(3)°. The (SnOAsO) 4 rings of 1 are linked and form a two‐dimensional network with the SnEt groups pointing into the holes of the next layer. Compound 2 occurs as a dimer with internal Sn(OMe) 2 Sn bridges in the (SnOAsO) 2 rings. The vibrational and mass spectra are given and discussed.