Oyster reef restoration efforts increasingly consider not only oyster recruitment, but also the recovery of ecological functions and the prevention of deploying harmful plastics. This study investigated the efficacy of a biodegradable plastic-alternative, BESE-elements®, in supporting oyster reef restoration in east-central Florida (USA) with consideration for how this material also influences biogeochemistry. Four experiments (two laboratory, two field-based) were conducted to evaluate the ability of BESE to serve as a microbial substrate, release nutrients, support oyster recruitment and the development of sediment biogeochemical properties on restored reefs, and degrade under field conditions. The results indicated BESE is as successful as traditional plastic in supporting initial reef development. In the lab, BESE accelerated short-term (10-day) sediment respiration rates 14-fold and released dissolved organic carbon, soluble reactive phosphorus, and nitrate to the surface water (71,156, 1980, and 87% increase, respectively) relative to without BESE, but these effects did not translate into measurable changes in reef sediment nutrient pools under field conditions. BESE lost 7–12% mass in the first year, resulting in a half-life of 4.4–6.7 years. Restoration practitioners should evaluate the biogeochemical properties of biodegradable materials prior to large-scale deployment and consider the fate of the restoration effort once the material degrades.

The impact of substituting Hg(II) for Zn(II) in a thiolate-bridged trinuclear cluster with parallels to a metallothionein metal cluster was investigated. A new solvomorph of [Zn(Zn L ) 2 ](ClO 4 ) 2 ( 1 ) ( L = N -(2-pyridylmethyl)- N -(2-(ethylthiolato)-amine) and five solvomorphs of a new compound [Hg(Zn L ) 2 ](ClO 4 ) 2 ( 2 ) were characterized by single-crystal X-ray crystallography. The interplay of hydrogen bonding and aromatic-packing interactions in producing lamellar, 2D lamellar, and columnar arrangements of complex cations in the crystalline state is discussed. Both variable temperature proton nuclear magnetic resonance and electrospray ion-mass spectrometry (ESI-MS) suggest that the complex ions of 1 and 2 are the predominant solution species at moderate concentrations. ESI-MS was also used to monitor differences in metal ion redistribution as 1 was titrated with Hg(ClO 4 ) 2 and [Hg L (ClO 4 )]. These studies document the facile replacement of Zn(II) by Hg(II) with the preservation of the overall structure in thiolate-rich clusters.

Metallothioneins (MTs) are a ubiquitous class of small cysteine-rich metal-binding proteins involved in metal homeostasis and detoxification with highly versatile metal binding properties. Despite the long-standing association of MT with M 3 S 3 and M 4 S 5 metal clusters, synthetic complexes with these core architectures are exceptionally rare. Here, we demonstrate an approach to synthesizing and characterizing aggregates of group 12 metal ions with monocyclic M 3 S 3 cores in acetonitrile solution without the protection of a protein. Multidentate monothiol ligand N,N-bis(2-pyridylmethyl)-2-aminoethanethiol (L1H) provided [Cd 3 (L1) 3 ](ClO 4 ) 3 (1), the first structurally characterized nonproteinaceous aggregate with a metallothionein-like monocyclic Cd 3 S 3 core. In addition, [Zn 3 (L1) 3 ](ClO 4 ) 3 •4CH 3 CN (2•4CH 3 CN) was characterized by X-ray crystallography. The complex cations of 1 and 2 had comparable structures despite being nonisomorphic. Variable temperature and concentration 1 H NMR were used to investigate aggregation equilibria of 1, 2, and a precipitate with composition "Hg(L1)(ClO 4 )" (3). Cryogenic 1 H NMR studies of 3 revealed a J( 199 Hg 1 H) coupling constant pattern consistent with an aggregate possessing a cyclic core. ESI-MS was used for gas-phase characterization of 1−3, as well as mixed-metal [M 2 M′(L1) 3 (ClO 4 ) 2 ] + ions prepared in situ by pairwise acetonitrile solution combinations of the group 12 complexes of L1. Access to synthetic variants of metallothionein-like group 12 aggregates provides an additional approach to understanding their behavior.