The tricyclic bisamidines 1 (2,2,2-) and 2 (3,2,3-) are pre-constrained to be syn-periplanar donors. Due to their different bite angles they have significantly different coordination modes. This has been confirmed by a variety of synthesized and characterized d-metal complexes including Pd(II), Cu(II), Zn(II) and Hg(II). To date, only the chelating coordination mode has been found for 2, while 1 exhibits both chelating and metal-bridging modes.