Synthesis, redox, spectroscopic, and photophysical properties of a new class of Pt(II) complexes of the type [PtLn -Cl](+) are reported, where L-n is 4'-phenyl(dimesitylboryl)-2,2':6',2''-terpyridine (L-1) or 4'-duryl(dimesitylboryl)-2,2':6',2''-terpyridine (L-2). The free L1 or L2 ligand in CH3CN shows the absorption band responsible for intramolecular charge transfer (CT) from the pi-orbital of the aryl group in L-1 or L-2 (pi(aryl)) to the vacant p-orbital on the boron atom (p(B)), in addition to pi pi* absorption in the 2,2': 6',2''-terpyridine (tpy) unit. In particular, the L1 ligand shows an intense CT absorption band as compared with L-2. Such intramolecular pi(aryl)-p(B) CT interactions in L1 give rise to large influences on the redox, spectroscopic, and photophysical properties of [PtL1Cl](+). In practice, [PtL1Cl](+) shows strong room-temperature emission in CHCl3 with the quantum yield and lifetime of 0.011 and 0.6 As, respectively, which has been explained by synergetic effects of Pt(II)-to-L-1 MLCT and pi(aryl)-p( B) CT interactions on the electronic structures of the complex. In the case of [PtL2Cl](+), the dihedral angle between the planes produced by the tpy and duryl(dimesitylborane) groups is very large (84 degrees) as compared with that between the tpy and phenyl(dimesitylborane) units in [PtL1Cl](+) (26-39 degrees), which disturbs electron communication between the Pt(II)-tpy and arylborane units in [PtL2Cl](+). Thus, [PtL2Cl](+) is nonemissive at room temperature. The important roles of the synergetic CT interactions in the excited-state properties of the [PtL1Cl](+) complex are shown clearly by emission quenching of the complex by a fluoride ion. The X-ray crystal structure of [PtL1Cl](+) is also reported.