Hydrothermal Synthesis and Structure of a Dinuclear Molybdenum(III) Hydroxy Squarate with a Mo-Mo Bond

Greg D Barber; Christy George; Kathryn Hogg; Shae T Johnstone; Carlos N Pacheco; Hemant P Yennawar; William G Van Der Sluys

doi:10.1021/acsomega.0c00083

Hydrothermal Synthesis and Structure of a Dinuclear Molybdenum(III) Hydroxy Squarate with a Mo-Mo Bond

ACS Omega. 2020 Feb 28;5(9):4668-4672. doi: 10.1021/acsomega.0c00083. eCollection 2020 Mar 10.

Authors

Greg D Barber¹, Christy George², Kathryn Hogg¹, Shae T Johnstone¹, Carlos N Pacheco², Hemant P Yennawar³, William G Van Der Sluys¹

Affiliations

¹ Department of Chemistry, The Pennsylvania State University, Altoona, Pennsylvania 16601, United States.
² Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16801, United States.
³ Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16801, United States.

Abstract

The reaction of molybdenum(II) and chromium(II) acetates with squaric acid in degassed and deionized water under hydrothermal conditions at 150 °C is described. The products have been formulated as M₂(μ-OH)₂(μ-C₄O₄)₂(H₂O)₄·2H₂O, where M = Cr (1) and Mo (2), based on combustion elemental analysis, infrared spectroscopy, magic angle spinning (MAS) solid-state carbon-13 nuclear magnetic resonance (NMR), and single-crystal X-ray diffraction. The edge-shared bioctahedral structures involve doubly bridging hydroxide ligands and μ-squarate ligands. The chromium compound lacks a direct metal-metal-bonding interaction, while in contrast the molybdenum compound contains a Mo-Mo bond [2.491(2) Å]. The nature of the Mo-Mo-bonding interaction is compared with that of other similar d³-d³ dimers.