In this work, insight into the Gd-Pt bond (of the heterometallic Ln-Pt complexes: ); PhSAc = thiobenzoate, NEt4 = tetraethylammonium)) was provided; single-crystal polarized X-ray absorption near edge structure (XANES) reveals the electronic states around the metal ion, where spectra of Gd-LIII edges show the Gd-Pt direction has the highest covalency (less ionic) around Gd ion in 2. In addition, natural bonding (NBO) analysis, natural population analysis (NPA), LOL, atoms in molecules (AIM), and ab initio calculations revealed the role of metallic and organic ligands in the electronic and magnetic properties of Ln complexes. PhSAc ligand is bulky, increases the intermolecular distance, and is effective in suppressing magnetic and intermolecular interactions between the Ln ions. Furthermore, it is effective for adding optical characteristics such as luminescence. The slow magnetization relaxation of the Gd complex was observed up to 45K, whic is the highest temperature reported to date among isolated Gd-complexes.