What are Research Chemicals?
"Research chemicals" literally refers to chemicals that are still being researched. Another term for them is "Experimental Chemicals" which may better communicate the unknown risks associated with ingesting them. When used to describe psychoactive drugs, it refers to new substances which haven't been thoroughly studied. Many are very new, while others may have been around for years but haven't been formally studied, used by many people, or had much data accumulated about their use. Very little is known about them, and much of what is known is based only on first-hand reports. Little if any research has been done on the toxicology or pharmacology of these drugs. Few, if any, human or animal studies have been done. Unlike better known drugs such as ecstasy, which has been taken by millions of people over 20+ years, or marijuana which has been used by billions of people over millennia, research chemicals are new and may only have been used by a few dozen people for a few months. The risks involved with research chemicals are far far greater than with most other drugs, since they're unknowns.
Most of the commonly know reseach chemicals come under the group of either Phenethylamine or Tryptamine. Although this is the case there is nothiong stopping other catorgory of chemicals being classified as research chemicals. In fact any new and experimental substance is technically a research chemical if it is used for human consuption.
There are far more chemical families than I can ever mention here (let alone individual chemicals), and after a couple of attempts to get things clear in my head and clean down on paper I have decided it just isn't possible. If for the moment we concentrate on Phenethylamines and Tryptamines exclusively you can start to see how huge a subject it is by have a look at Alexander Shulgin's PIHKAL and TIHKAL, both of which have been heavy catalogued on here. Just a quick look will give you an idea of the size of the suject, with PHIKAL having 179 entries, while PIKAL weighs in with only 55.
On top of these there are new possibilities still being discovered within these main groups, each of which can be divided into sub-groups. There is also new chemicals within other known groups and completely new chemicals being discovered, such as IAP, which have known known analogue and can thus slip past the new drugs laws banning chemicals based on their similarity to currently controlled substances.
The law and research chemicals:
Due to the way the drugs laws worked until recently it was relatively easy to get new research chemicals as they had to be made illegal as each substance was discovered or invented. Many new chemicals were appearing as herbal highs before they were classified. This caused a lot of countries to bring in a Analogue Drug Act which makes many chemicals illegal without having to manually schedule them as a controlled substance. It is still possible to find vendors of Research Chemicals, but most countries have laws against it, and any transactions are closely monitored. A lot of the companies that were supplying these chemicals are curently under investigation, or going through court proceedings. As with any legal matter the subject is huge, and far beyond what I could go into here even if I did know all the ins and outs for every country on our green planet.
Sources:
http://www.erowid.org
and the kind people at http://www.bluelight.nu