Di-n-but-yl{4-hydr-oxy-N'-[(2-oxido-1-naphthyl-κO)methyl-ene]benzo-hydrazidato-κO,N'}tin(IV).

The deprotonated Schiff base ligand in the title compound, [Sn(C(4)H(9))(2)(C(18)H(12)N(2)O(3))], O,N,O'-chelates to the Sn atom, which is five-coordinated in a cis-C(2)NO(2)Sn trigonal-bipyramidal environment. The apical sites are occupied by the O atoms [O-Sn-O = 155.2 (2)°]. The hydr-oxy group is a hydrogen-bond donor to the two-coordinate N atom of an adjacent mol-ecule, the hydrogen-bonding inter-action giving rise to a helical chain running along the c axis. The carbon atoms of the butyl chains are equally disordered over two positions.