Quite a number of years ago now, an article appeared in Analog magazine by Stephen L. Gillett concerning terraforming Venus. In it, he speculated that one way to get rid of the excess carbon dioxide in Venus’s atmosphere might be to convert it into what he termed “diamond ether”. Diamond ether is a hypothetical solid with an empirical formula of CO2. It’s molecular structure would be similar to diamond (each carbon atom linked tetrahedrally to four others), only with an intermediary oxygen atom between each two carbon atoms (hence the “ether” part). Or to put it another way, it would be the carbon analog of the silicate mineral cristobalite. Other writers have used the term “carba” in analogy to silica as a name for any of a class of such hypothetical solids.
At the time Gillett wrote his article, no one to the best of his knowledge had ever tried to synthesize this material. It would be metastable compared to gaseous CO2, but the big question was how metastable? Something that would explode at anything less than cryogenic temperature? Or rapidly decompose if exposed to water or air? Or a long-lived metastable solid like diamond?
My searches on the web have revealed absolutely nothing new on this subject; only reprints of the original article and commentaries on it. Considering how concerned people are about finding ways to sequester CO2, I’m surprised nothing more has come of this. Has anyone done any more work on the subject one way or the other?
The trouble with such a material is the hybridization of the connecting oxygen. Oxygen is happiest with the sp3 hybridization which requires an angle between the two carbons. The only possible hybridization (available to Oxygen.) that would allow a linear geometry would be sp. That would leave Oxygens two lone pairs in unhybridized non-bonding p orbitals. Without some type of stabilization like resonance these orbitals are really high in energy.
I am almost certain that such a material as “diamond-ether” as you called it, could not exist for long. It would decompose quite explosively as it would generate CO2.
But we already have in our possession to convert CO2 into a solid form of carbon in a cheap and cost effective manner: plants.
I imagine that planting trees and cutting them down, burying the wood to sequester the carbon, and planting more trees is cheaper than creating “diamond ether.”
I see from the paper, he is not refering to the structure of diamond, more of glass with carbon. In which case my orbital argument is not valid. Carbon in such a molecule would be extremely electropositive. At the same time it would be surrounded by a high concentration of negative charge on the oxygens. Those two things would likely react very quickly. Since the product of the reaction is an extremely low energy gas it is unlikely that the barrier would be high. Based on Hammonds postulate the transition state would be really early, meaning that very little rearrangement would be required to make the whole thing react. Metastable is being too kind.
Keep in mind the author of that paper was a Sci Fi writer with as far as I can tell, no chemistry qualifications. His PhD is in Geology from what I read. The only journal I recognize is Angewante, and that article is on something only vaguely related. In short this paper is a work of fiction.