Pearson, Wright L., IIICopeland, ChristopherKocak, AbdulkadirSallese, ZacharyMetz, Ricardo B.2015-05-082015-05-082014-11-24http://hdl.handle.net/2097/19234The electronic spectra of Mn[superscript +](H[subscript 2]O) and Mn[superscript +](D[subscript 2]O) have been measured from 30 000 to 35 000 cmˉ¹ using photodissociation spectroscopy. Transitions are observed from the 7A1 ground state in which the Mn+ is in a 3d[superscript 5]4s¹ electronic configuration, to the [superscript 7]B[subscript 2] (3d 54p y) and 7B1 (3d[superscript 5]4p[subscript x]) excited states with T[subscript 0] = 30 210 and 32 274 cmˉ¹, respectively. Each electronic transition has partially resolved rotational and extensive vibrational structure with an extended progression in the metal−ligand stretch at a frequency of ∼450 cmˉ¹. There are also progressions in the in-plane bend in the [superscript 7]B[subscript 2] state, due to vibronic coupling, and the out-of-plane bend in the [superscript 7]B[subscript 1] state, where the calculation illustrates that this state is slightly non-planar. Electronic structure computations at the CCSD(T)/aug-cc-pVTZ and TD-DFT B3LYP/6-311++G(3df,3pd) level are also used to characterize the ground and excited states, respectively. These calculations predict a ground state Mn-O bond length of 2.18 Å. Analysis of the experimentally observed vibrational intensities reveals that this bond length decreases by 0.15 ± 0.015 Å and 0.14 ± 0.01 Å in the excited states. The behavior is accounted for by the less repulsive px and py orbitals causing the Mn[superscript +] to interact more strongly with water in the excited states than the ground state. The result is a decrease in the Mn-O bond length, along with an increase in the H-O-H angle. The spectra have well resolved K rotational structure. Fitting this structure gives spin-rotation constants ɛ[subscript aa]″ = −3 ± 1 cmˉ¹ for the ground state and ɛ[subscript aa]′ = 0.5 ± 0.5 cmˉ¹ and ε[subscript aa]′ = −4.2 ± 0.7 cmˉ¹ for the first and second excited states, respectively, and A′ = 12.8 ± 0.7 cmˉ¹ for the first excited state. Vibrationally mediated photodissociation studies determine the O-H antisymmetric stretching frequency in the ground electronic state to be 3658 cmˉ¹.en-USThis Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).Excited statesGround statesZincPhotodissociationNickelArticle (publisher version)