Polymerised Water

In my opinion, probably the least distinguished moment in science in the last sixty years occurred in the late 1960s, and not for the seemingly obvious reason. It all started when Nikolai Fedyakin condensed steam in quartz capillaries and found it had unusual properties, including a viscosity approaching that of a syrup. Boris Deryagin improved production techniques (although he never produced more than very small amounts) and determined a freezing point of – 40 oC, a boiling point of » 150 oC, and a density of 1.1-1.2. Deryagin decided there were only two possible reasons for this anomalous behaviour:

(a) the water had dissolve quartz,

(b) the water had polymerised.

Since recently fused quartz is insoluble in water at atmospheric pressures, he concluded that the water must have polymerised. There was no other option. An infrared spectrum of the material was produced by a leading spectroscopist from which force constants were obtained, and a significant number of papers were published on the chemical theory of polywater. It was even predicted that an escape of polywater into the environment could catalytically convert the Earth’s oceans into polywater, thus extinguishing life. Then there was the inevitable wake-up call: the IR spectrum of the alleged material bore a remarkable resemblance to that of sweat. Oops. (Given what we know now, whatever they were measuring could not have been what everyone called polywater, and probably was sweat, and how that happened from a very respected scientist remains unknown.)

This material brought out some of the worst in logic. A large number of people wanted to work with it, because theory validated it existence. I gather the US navy even conducted or supported research into it. The mind boggles here: did they want to encase enemy vessels in toffee-like water, or were they concerned someone might do it to them? Or even worse, turn the oceans into toffee, and thus end all life on Earth? The fact that the military got interested, though, shows it was taken very seriously. I recall one paper that argued Venus was like it is because all its water polymerised!

Unfortunately, I think the theory validated the existence because, well, the experimentalists said it did exist, so the theoreticians could not restrain themselves from “proving” why it existed. The key to the existence is that they showed through molecular orbital theory that the electrons in water had to be delocalized. Most readers won’t see the immediate problem because we are getting a little technical here, but to put it in perspective, molecular orbital theory assumes the electrons are delocalized over the whole molecule. If you further assume water molecules come together, the firsr assumption requires the electrons to be delocalised, which in turn forces the system to become one molecule. If you cannot end up with what you assumed in the first place, your theoretical work is not exactly competent, let alone inspired.

Unfortunately, these calculations involve what are called quantum mechanics. Quantum mechanics is one of the most predictive theories ever, and almost all your electronic devices have parts that would not have been developed but for knowledge of quantum mechanics. The problem is that for any meaningful problem there is usually no analytical solution from the formal quantum theory generally used, and any actual answer requires some rather complicated mathematics, and in chemistry, because of the number of particles, some approximations. Not everyone agreed. The same computer code in different hands sometimes produced opposite results with no explanation of why the results differed. If there were no differences in the implied physics between methods that gave opposing results, then the calculation method was not physical. If there were differences in the physics, then these should have been clearly explained. The average computational paper gives very little insight to what is done and these papers were actually somewhat worse than usual. It was, “Trust me, I know what I’m doing.” In general, they did not.

So, what was it? Essentially, ordinary water with a lot of dissolved silica, i.e. option (a) above. Deryagin was unfortunate in suffering in logic from the fallacy of the accident. Water at 100 degrees C does not dissolve quartz. If you don’t believe me, try boiling water it in a pot with a piece of silica. It does dissolve it at supercritical temperatures, but these were not involved. So what happened? Seemingly, water condensing in quartz capillaries does dissolve it. However, now I come to the worst part. Here we had an effect that was totally unexpected, so what happened? After the debacle, nobody was prepared to touch the area. We still do not know why silica in capillaries is so eroded, yet perhaps there is some important information here, after all water flows through capillaries in your body.

One of the last papers written on “anomalous water” was in 1973, and one of the authors was John Pople, who went on to win a Nobel Prize for his work in computational chemistry. I doubt that paper is one that he is most proud of. The good news is the co-author, who I assume was a post-doc and can remain anonymous because she almost certainly had little control on what was published, had a good career following this.

The bad news was for me. My PhD project involved whether electrons were delocalized from cyclopropane rings. My work showed they were not however computations from the same type of computational code said it did. Accordingly, everybody ignored my efforts to show what was really going on. More on this later.

Scientific low points: (2)

The second major low point from recent times is polywater. The history of polywater is brief and not particularly distinguished. Nikolai Fedyakin condensed water in, or repeatedly forced water through, quartz capillaries, and found that tiny traces of such water could be obtained that had an elevated boiling point, a depressed freezing point, and a viscosity approaching that of a syrup. Boris Deryagin improved production techniques (although he never produced more than very small amounts) and determined a freezing point of – 40 oC, a boiling point of » 150 oC, and a density of 1.1-1.2. Deryagin decided there were only two possible reasons for this anomalous behaviour: (a) the water had dissolved quartz, (b) the water had polymerized. Everybody “knew” water did not dissolve quartz, therefore it must have polymerized. From the vibrational spectrum of polywater, two new bands were observed at 1600 and 1400 cm-1. From force constant considerations this was explained in terms of each OH bond being of approximately 2/3 bond order. The spectrum was consistent with the water occurring in hexagonal planar units, and if so, the stabilization per water molecule was calculated to be in the order of 250-420 kJ/mol. For the benefit of the non-chemist, this is a massive change in energy, and it meant the water molecules were joined together with a strength comparable to the carbon – carbon bonds in diamonds. The fact that it had a reported boiling point of » 150 oC should have warned them that this had to be wrong, but when a bandwagon starts rolling, everyone wants to jump aboard without stopping to think. An NMR spectrum of polywater gave a broad, low intensity signal approximately 300 Hz from the main proton signal, which meant that either a new species had formed, or there was a significant impurity present. (This would have been a good time to check for impurities.) The first calculation employing “reliable” methodology involved ab initio SCF LCAO methodology, and water polymers were found to be stabilized by polymer size. The cyclic tetramer was stabilized by 177 kJ/mol, the cyclic pentamer by 244 kJ/mol, and the hexamer by 301.5 kJ/mol. One of the authors of this paper was John Pople, who went on to get a Nobel prize, although not for this little effort.

All of this drew incredible attention. It was even predicted that an escape of polywater into the environment could catalytically convert the Earth’s oceans into polywater, thus extinguishing life, and that this had happened on Venus. We had to be careful! Much funding was devoted to polywater, even from the US navy, who apparently saw significant defence applications. (One can only imagine the trapping of enemy submarines in a polymeric syrup, prior to extinguishing all life on Earth!)

It took a while for this to fall over. Pity one poor PhD candidate who had to prepare polywater, and all he could prepare was solutions of silica. His supervisor told him to try harder. Then, suddenly, polywater died. Someone notice the infrared spectrum quoted above bore a striking resemblance to that of sweat. Oops.

However if the experimentalists did not shine, theory was extraordinarily dim. First, the same methods in different hands produced a very wide range of results with no explanation of why the results differed, although of course none of them concluded there was no polywater. If there were no differences in the implied physics between methods that gave such differing results, then the calculation method was not physical. If there were differences in the physics, then these should have been clearly explained. One problem was, as with only too many calculations in chemical theory, the inherent physical relationships are never defined in the papers. It was almost amusing to see, when it was clear there was no polywater, a paper was published in which ab initio LCAO SCF calculations with Slater-type orbitals provide evidence against previous calculations supporting polywater. The planar symmetrical structure was found to be not stable. A tetrahedral structure made by four water molecules results in instability because of excessive deformation of bond angles. What does that mean, apart from face-covering for the methodology? If you cannot have roing structures when the bond angles are tetrahedral, sugar is therefore an impossible molecule. While there are health issues with sugar, impossibility of its existence is not in debate.

One problem with the theory was that molecular orbital theory was used to verify large delocalization of electron motion over the polymers. The problem is, MO theory assumes it in the first place. Verifying what you assume is one of the big naughties pointed out by Aristotle, and you would thing that after 2,400 years, something might have stuck. Part of the problem was that nobody could question any of these computations because nobody had any idea of what the assumed inputs and code were. We might also note that the more extreme of these claims tended to end up in what many would claim to be the most reputable of journals.

There were two major fall-outs from this. Anything that could be vaguely related to polywater was avoided. This has almost certainly done much to retard examination of close ordering on surfaces, or on very thin sections, which, of course, are of extreme importance to biochemistry. There is no doubt whatsoever that reproducible effects were produced in small capillaries. Water at normal temperatures and pressures does not dissolve quartz (try boiling a lump of quartz in water for however long) so why did it do so in small capillaries? The second was that suddenly journals became far more conservative. The referees now felt it was their God-given duty to ensure that another polywater did not see the light of day. This is not to say that the referee does not have a role, but it should not be to decide arbitrarily what is true and what is false, particularly on no better grounds than, “I don’t think this is right”. A new theory may not be true, but it may still add something.

Perhaps the most unfortunate fallout was to the career of Deryagin. Here was a scientist who was more capable than many of his detractors, but who made an unfortunate mistake. The price he paid in the eyes of his detractors seems out of all proportion to the failing. His detractors may well point out that they never made such a mistake. That might be true, but what did they make? Meanwhile, Pople, whose mistake was far worse, went on to win a Nobel Prize for developing molecular orbital theory and developing a cult following about it. Then there is the question, why avoid studying water in monolayers or bilayers? If it can dissolve quartz, it has some very weird properties, and understanding these monolayers and bilayers is surely critical if we want to understand enzymes and many biochemical and medical problems. In my opinion, the real failures here come from the crowd, who merely want to be comfortable. Understanding takes effort, and effort is often uncomfortable.