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Abstract
The existence of high spin Cr(II), Fe(II), Mn(II), and Co(II) in square planar coordination isremarkable in coordination chemistry, and these metal centers exhibit unique magnetic and
electronic properties. The chromium metal tetrasilicates, ACrSi4O10 (A= Ca, Sr, and Ba), are rare
examples of high spin Cr(II) in square-planar coordination. Though the synthesis and structure of
ACrSi4O10 has been known for several decades, much of the related chemistry remains unknown.
Thus, this study describes the crystal growth and nanostructuring of these ACrSi4O10
tetrasilicates. For the first time, this work addresses the preparation of mixed tetrasilicates
containing Fe(II)/Cr(II), Fe(II)/Mn(II), Fe(II)/Co(II), and Cr(II)/Mn(II) in the known BaBSi4O10
crystal lattice. Chapter II discusses the chemistry of ACrSi4O10 including their syntheses and
crystal growth through improved solid state and flux-based methods. This chapter also reviews
the utilization of a metal envelope made from folded Cr foil to maintain a low oxygen fugacity in
the reaction environment. Chapter 3 demonstrates the syntheses of mixed metal tetrasilicates,
including Ba(Fe,Cr)Si4O10, Ba(Fe,Mn)Si4O10, Ba(Fe,Co)Si4O10, and Ba(Cr,Mn)Si4O10. This
chapter explains the success of a template-based approach for the incorporation of a second
metal into the known BaBSi4O10. Chapter 4 discusses the nanostructuring of ACrSi4O10,
Ba(Fe,Cr)Si4O10, Ba(Fe,Mn)Si4O10, and Ba(Cr,Mn)Si4O10 via the top-down approach. Overall,
this research expands the chemistry of metal tetrasilicates into new directions.