Biguanide complexes of baron have been investigated as potential exter
ior grade fixed boron wood preservatives. Two biguanide rings are nece
ssary for achieving moderate hydrolytic stability in application to wo
od. The complexes B(big)(OH)(2) (I) and B(big)(2)Cl (2) (big = biguani
de) have been investigated by B-11 and C-13 NMR spectroscopy and their
structures determined by X-ray crystallography.