The highly resolved electronic spectrum of the square planar CuCl42− ion

Abstract

Articles you may be interested inAbsence of exchange interaction between localized magnetic moments and conduction-electrons in diluted Er3+ gold-nanoparticles J. Appl. Phys. 115, 17E128 (2014) The low temperature magnetic circular dichroism ͑MCD͒ and electron paramagnetic resonance ͑EPR͒ spectra of Cu͑II͒ doped Cs 2 ZrCl 6 are reported. The Cu͑II͒ ion is incorporated as the square planar copper tetrachloride ion, CuCl 4 2− , which substitutes at the Zr͑IV͒ site in the Cs 2 ZrCl 6 lattice, with a complete absence of axial coordination. Both the EPR and MCD show highly resolved spectra from which it is possible to determine the superhyperfine coupling constants and excited state geometries respectively. The Franck-Condon intensity patterns suggest that there is a substantial relaxation of the host lattice about the impurity ion. For the lowest energy 2 B 1g ͑x 2 -y 2 ͒ → 2 B 2g ͑xy͒ transition, both the magnetic dipole allowed electronic origin as well as vibronic false origins are observed. The high resolution of the spectra allowed the accurate determination of the odd parity vibrations that are active in the spectra. The opposite sign of the MCD of the two components of the 2 E g ͑xz , yz͒ excited state allows this splitting to be determined for the first time. Accurate and unambiguous spectral parameters for the CuCl 4 2− ion are important as it has become a benchmark transition metal complex for theoretical electronic structure calculations.

Photochromism in Ruddlesden–Popper copper-based perovskites: a light-induced change of coordination number at the surface

“…Raman spectroscopy has been used to characterize the vibrational modes of various copper chloride complexes. [19][20][21] Our Raman spectrum collected from a single crystal of (PEA) 2-CuCl 4 (Fig. 2) has clear peaks at 179, 247 and 287 cm À1 , and is very similar to the low-frequency regime spectrum reported by Caretta et al 22 These peaks are all assigned to vibrational modes of Cu-Cl bonds: n 2 (A 1g ), n 4 (B 2g ) and n 1 (A 1g ), respectively.…”

“…displays ligand-field transitions between 500 and 850 nm. 43,44 The formation of CuCl 4 2À can also explain the shift in the UV-region of the absorption spectrum, because these ions have an absorption peak around 267-270 nm, matching perfectly with our spectrum. 45,46 In addition, the new Raman peak can be attributed to square-planar CuCl 4 2À : the totally symmetric stretch of the ion is found at 271 cm À1 .…”

Outer-Sphere Contributions to the Electronic Structure of Type Zero Copper Proteins

“…The C112D MCD spectrum closely resembles that reported for square-planar [CuCl 4 ] 2− , 44 except that all transitions are shifted to lower energies than in CuCl 4 2− . This result is not surprising in view of the similarity between the spin-Hamiltonian parameters of CuCl 4 2− and C112D azurin.…”

“… a Rhombicity, R g = 2(Δ g y − Δ g x )/(Δ g y + Δ g x ); Δ g i = g i − g e . b Parallel component of the 63,65 Cu hyperfine. c Single-crystal W-band data from ref 40 for components of g , frozen solution L- and S-band data in ref 41 for hyperfine splittings. d From single crystal Q-band in ref 44. …”

Investigations of the spin-Hamiltonian parameters and defect structure due to Jahn–Teller effect for the tetragonal Nb4+center in cubic Cs2ZrCl6crystal

“…converting the near-infrared excitation into visible luminescence) (1)(2)(3)(4)(5). So, the spectroscopic properties of the doped Cs 2 ZrCl 6 crystals have attracted attention (1)(2)(3)(4)(5)(6)(7)(8)(9). Decades ago, the electron paramagnetic resonance (EPR) spectrum of Nb 4+ -doped Cs 2 ZrCl 6 was measured (9).…”