Synthesis of ruthenium(II) monosubstituted squarates: 2. Single crystal structures of fac-[Ru(Cl)(dmso)3(H2O)(L)] · xH2O (L=anisole-, anilino-squarate) and fac-[Ru({C6H5}2NC4O3)(Cl)(dmso)3(H2O)] · C4H8O ☆