Impact of different environmental stimuli on the release of 1-MCP from boron-MCP complexes.

In our previous report, boron derivatives of methylene cyclopropane complexes (B-MCP) were developed to stabilize the gaseous 1-MCP (1-methylcyclopropene), a commercial plant growth regulator, for eventual release in open crop fields when under humid conditions or in contact with water. To meet the requirements of various end-use applications, B-MCP compounds that can release 1-MCP at different rates for different time periods are demanded. In this paper, we examined the impact of different environmental stimuli such as humidity, surface area, water pH and water volume on the release kinetics of 1-MCP from B-MCP compounds of various chemical structures. The results showed that the release of 1-MCP from B-MCP compounds can be tailored by altering the architectures and chemical natures of the two short-chain moieties attached to the boron atom and thus either the electronic affinity or the hydrophobic or hydrophilic properties or both.