You know, it seems like there is a direct relationship between how satisfying and tasty and generally yummy a food is, and how unhealthy it is considered for you.
I've often thought there is a definitive, aethereal and tenuous, but nevertheness distinctly real similar principle at play in the availability, or at least reasily either improvizable or adaptable or over-the-counter or even ebay at a stretch-able ness of a chemical element or more complicated reagent or reagent class, and how useful it or its class are as a whole, useful to the hobby scientist.
Basically, the more useful and desirable the reagent is, the more hard to get hold of, watched by undesirable three-letter-agencies if they are able to, meaning a hobbyist has to learn how to avoid being flagged on the watch lists of various undesirables...the more desirable, it has a direct and scalar relationship between desirability and inverse reciprocal of availability.
The more a hobby chemist would covet it and desire it, the harder it is to buy without having built up one's personal supply and demand fulfilment networks over the years of having dedicated one's soul to the pursuit of the study of chemistry in all its guises, the harder it is to make , the harder it is to confine and keep from destroying itself, and the more dangerous it is. I.e, alkali metals, lithium, sodium, potassium are hard to store, once hermetically sealed canisters and wrappers are breached, despite being stored under vacuum degassed, argon-sparged anhydrous mineral oil dried first over 3A molecular sieves.
Still degrade over time in stasis on the lab shelves despite stringent precautions being taken to avoid oxidation. And reagents like sodium and potassium hydride, lithium aluminium hydride-LiAlH4 aka LAH, or Lith-Al for short, its violently reactive towards traces of atmospheric water vapor, catching fire, having to be used with carefully pre-dried for the purpose solvents, transferred from flame-dried or oven-dried containers to reaction vessels similarly directly flame-dried or oven dried then sealed with self-healing polymer septa, even the glass syringes and the steel flexible, long needles for transport need the trace levels of water adhering to their surfaces driving off, and the solvents used to prepare the solutions LAH and most other hydrides are used with, such as THF and diethyl ether dried with very aggressive multi-stage chemical stages generally ending with something like distillation from potassium or sodium metal.
And they have to be, most of them at least, used under inert atmospheres such as argon or helium dried by passage through bubblers filled with things like 100% sulfuric acid, phosphorus pentoxide,. with some padding to avoid acid spatter from the bubblers carrying through acid mists, with violent and disastrous consequences for the chemist.
And, hydride based reducing agents are allmost all of them very very difficult to purchase them, to get someone in your suppliers networks who will supply the materials needed to you,
They are expensive when you do get your hands on any, take strongent storage precautions and usage techniques, and generally take a chemist with the faculties to manage their use in a calm, collected, cool-headed manner, most of them are pyrophoric, bursting into flames if they contact atmospheres containing oxygen or oxidizing gases of other natures.
And the less useful the particular hydride, for many different varieties have been synthesized with different quirks and specialities and areas in which they excell at reducing one particular group while tolerating and being mild on another type, etc., the less such qualities are to be found, the more affordable, the easier it is to get hold of, the less watched, some, such as sodium borohydride can even be used in not just solvents that haven't been aggressively stripped of the tiniest traces of water and oxygen, but in a vigorously stirred aqueous-alcoholic medium of isopropanol and water,
Although it isnt to say NaBH4 isn't without its uses. There are numerous artful combinations and tricks with things like metal salts, metal nanoparticles, in the likes of different acidic or acid-salt systems, such as in-situ formation of triacetoxyborohydride, triethylborohydride, cyanoborohydride, as well as variying the cation and the modification of borohydride anion.
And NaBH4 is easily obtainable, its not overpricey, has a great shelf life even as a powder, although I buy mine as the super-convenient pre-weighted 1-gram-per-pellet prills, that have been pressed into tablet form, I don't NEED to, but I try to improve life still further by purging my bottle of borohydride with dry argon gas when opening and closing the bottle but even as powder it can last YEARS, and no bursting into flame; main specific hazard is with cyanoborohydrides and cyanide gas precaution as standard for cyanide evolution potential typical. for acid-reactive cyanide anion sources.
As it is, its generally a rather mundane reducing agent, with no real shining characteristics other than its stability , water tolerance, air tolerance, and tolerance to protic environments. But there are so many other derivatives of borohydride that can be formed in-situ from NaBH4 or LiBH4 for making things like lithium triethylborohydride, metal salts to form ultra-finely divided metal manoparticles. Sort of similar to how Rieke metals are prepared using metallic potassium or sodium to reduce metal salts to super finely divided metals with a high surface area and consequently very, very, extremely reactive nature for the metal in quesion, performing tasks for it, such as forming otherwise-impossible Grignard reagents in the case of Riecke magnesium.
Nanotech reduction methods employing borohydride are just beginning to be explored in the clandestine chemist's world, and it remains to be deduced what the functional group tolerances and reductant capabilities are for various different structures. But, the very first time I ever used the borohydride based in-situ formation of nanoparticulate copper for example, it provided smooth reduction of my substrate in not too bad yields. That for the very first time, it performed admirably, not bad yields either. And that for a very, very first time using the reaction.
