NIR-VIS reflectivity spectra of some transition metal thiophosphates

Abstract

Room temperature optical-reflectivity measurements on some transition metal thiophosphates were carried out in the near infrared and visible regions. The resulting spectra, interpreted on the basis of the <<transition metal weakly interacting>> model, agree well with earlier optical transmission measurements. Below the fundamental absorption edge, the observed features have been assigned to 3d-3d transitions occurring on the transition metal ion, while those observed at photon energies greater than the absorption threshold have been attributed to transitions from the valence bands to discrete 3d orbital levels or to the conduction bands. A more detailed information on the metal ion 3d levels energy distribution with respect to the valence band states belonging to the (P2S6)4- cluster and a more precise determination of the MPS3 absorption edge energy position have been obtained

First copper(ii) phase M′0.2Mn0.8PS3·0.25H2O and analogous M′ = CoII, NiII and ZnII materials obtained by microwave assisted synthesis

“…5,[28][29][30] The band structure for several MPS 3 phases has been widely studied and a detailed description of the electronic structure responsible for the absorption edge is now available. [31][32][33][34] In conclusion, it has been assessed that the partially filled 3d orbitals could be responsible for the electron acceptor capability of the corresponding phase. 4 Calculations done by Mercier et al have shown that the pristine Mn II phase shows the highest absorption edge as compared with Fe II and Co II , while for the Ni II phase, an increase in energy of the absorption edge is expected.…”

Manganese(ii) thiophosphate (MnPS3) intercalates with lanthanide (PrIII and NdIII) complexes: optical and magnetic properties

“…The former is mainly constructed from 3p z (P–P) orbitals, while the latter is predominantly associated with anti-bonding orbitals 3p z *(S). 33 Upon intercalation, the 3p z *(S) state energy may be lowered, resulting in an observed lower band gap energy value.…”

Macrocyclic ZnII and CuII complexes as guests of the hybrid composites based on the layered MnPS3 phase. Comparison of spectroscopic properties

“…The conduction band at higher energy corresponds to the antibonding 3p z of the P-P bond and sulfur [46]. According to Grasso, the main absorption band at 2.5 eV is from the valence band formed by the 3p x p y and 3s orbitals of the P-S bond to the atomic orbitals of the manganese ion [47][48][49]. As shown in table 3, all composites have spectra with energy gaps lower than the pristine MnPS 3 phase (2.5 eV).…”