The mechanism of the excited-state dynamics of VCl 3 (ddpd)is shown in Figure . The dynamics are started by exciting in an energy region of 3-3.5 eV which populates mainly (90%) thatin idealized octahedral symmetry -belong to the 3 T 1 ′ term of the t 1 2g e 1 g electron configuration (dark blue box). These states are split energetically as the complex is only of pseudo-octahedral symmetry (see Section S3). However, through analysis of their wave function they can be unambiguously assigned to the 3 T 1 ′ term. Thus, to simplify the discussion of the excited-state dynamics, we will use this pseudo-octahedral notation for the states of the 3 T 1 ′ term as well as for all other metal-centered states. From the 3 T 1 ′ states, the population is transferred via internal conversion into A 2 states of e g configuration (light-blue box) and via intersystem crossing into singlet states belonging to the 1 E, 1 T 2 and 1 A 1 terms of the t 2 2g electron configuration (violet box). These singlet states are simply denoted as "Sing." in Figure for completeness we note, however, that the 1 A 1 term is not a pure t 2 2g state but possesses notable admixture of t 1 2g e 1 g character. Both internal conversion and intersystem crossing account for ca. half of the population starting in the 3 T 1 ′ states. From the 3 A 2 states, the population relaxes via 3 T 2 states of t 1 2g e 1 g configuration (green box) to the states of the 3 T 1 term of the t 2 2g configuration (red box) which represents the ground state of VCl 3 (ddpd). From the singlet states, most population also relaxes via the 3 T 2 states to the 3 T 1 ground states. However, importantly, a fraction of ca. 10% of the overall populations remains stable in the singlet states even after long simulation times of 100 ps; this population then can account for the observed photoluminescence of VCl 3 (ddpd). In addition, small parts of the population are initially excited to so-called DL states (7%, orange box) and the 3 A 2 states (3%) which also decay via the 3 T 2 states to the 3 T 1 ground states. The 3 DL states can be described by a combination of single excitations from the ligand π to the ligand π * orbitals and a (π, d)→(π * , d) double excitations involving the ligand π/π * and vanadium-d orbitals. Based on the electronic character of the states involved in the excited-state dynamics mechanism of VCl 3 (ddpd), we proposed a two-part hypothesis that by increasing the ligand-field splitting, higher photoluminescence yields could be obtained in related complexes. The hypothesis could be rationalized in the following manner: increasing the ligand-field splitting raises the energy of the antibonding e g orbitals while the energy of non-bonding t 2g orbitals is unaffected. The shifting of the orbital energies will result in a destabilization of all electronic states that possess electrons in e g orbitals as indicated by the red arrows in Figure (b), which could influence the excited-state dynamics mechanism in two ways. First, by increasing the energy of of the 3 A 2 states of e 2 g character, the 3 T ′ 1 → 3 A 2 reaction could be partially quenched. As this is the competing pathway of the population of the singlet states via intersystem crossing, its quenching could increase the amount of population that is transferred to the singlet manifold. Second, by increasing the energy of the 3 T 2 states, the Sing→ 3 T 2 depopulation of the singlet manifold could be quenched, which would leave more population in the singlet manifold to increase the photoluminescence yield. Both parts of the hypothesis will be referred to as hypothesis I and hypothesis II in the discussion lateron.