Six companies were asked to design prototypes. These were: Gustloff-Werke, Mauser, Johannes Großfuß Metall- und Lackierwarenfabrik, C.G. Hänel, Rheinmetall-Borsig and Heinrich Krieghoff Waffenfabrik. Several contracts were given out, but only a few prototypes are known to have been given. Mauser gave a version of the MG 81. However, it was turned down because it was too heavy and got its bullets from a belt. There was one design, made by Louis Stange at Rheinmetall-Borsig, that was accepted. It was tested at a test station at Tarnewitz in mid-1942. This prototype was called Gerät" 450 ("device 450") or Ausführung" "A" ("type A"). It was supposed to be a sheet metal design. The type "A" was never made (except for some models). However, the basic design was kept for more development.
The basic parts of the LC-6 were accepted. A group of changes to the design came afterwards. The improved version of the LC-6 was called the "Ausführung" "B". This improvement changed the hand guard so that it gave better protection against heat and a better grip when it was wet.
These tests showed many problems. They were fixed by Stange in April 1942. This other improved version was called the LC-6/II. The prototype was then given many tests. These tests were set up by the HWA. The prototype was changed even more, and finally it became the LC-6/III prototype. This became the FG 42.
50 rifles were made in early 1943. Six of these were sent away to be tested more. These weapons had some serious faults. One rifle failed after firing only 2,100 rounds. Also, a soldier was injured when he tried to fire a rifle grenade.
Several other changes were made to the FG 42 before it was allowed to be made. The first Rheinmetall design used chrome-nickel steel a lot. It was used on many parts which were needed to make the weapon work. There was not much of this material around. When the "Luftwaffe" was allowed to make 3,000 rifles for some more testing, the weapon was changed and manganese steel was used instead of chrome-nickel steel. The Heinrich Krieghoff company was asked to make some FG 42s. This was because Rheinmetall was not large enough to make lots of FG 42s. The weapon was first used by commandos during "Operation Eiche" in 1943. "Operation Eiche" was the dangerous mission that some "Fallschirmjäger" went on. During this mission, they had to rescue Benito Mussolini. The "Fallschirmjäger" team was led by Otto Skorzeny.
The weapon kept being changed. Because its first design was changed many times and the "Luftwaffe" needed different things, many different types of FG 42 were made. Papers and books written after World War II usually say that there were three main versions of FG 42. However, the Germans never said that they were different models. The "Model I", "Model II" and "Model III" were never officially mentioned. German papers just call the weapon the "FG 42". It was always the latest version of FG 42 that was mentioned.
The BD 42/I is a semi-automatic copy of the early FG 42 rifle. The BD 42/II is a semi-automatic copy of the later FG 42. Both of these were made by HZA Kulmbach GmbH.
The FG 42 was a selective fire weapon. It was cooled by the air. The FG 42 also had its magazine at the side. It was quite easy to control if it was being fired on fully automatic mode.
The FG 42 got its bullets from a box-shaped magazine. This magazine could hold 10 or 20 rounds.
The FG 42 was semi-automatic when it was being fired from a closed bolt. There was not very much movement when the weapon was being fired. This meant that firing single shots was more accurate. When the weapon was being fired in automatic mode, it was fired from an open bolt. When automatic mode was on, the bolt stayed open to keep the weapon cool.
The FG 42 was supposed to give some useful firepower to Nazi Germany. However, only a small amount were made. When it was tested, the paratroopers quite liked it. However, the FG 42 did have some issues. The FG 42 had a 20, or sometimes 10, round magazine which was put into the left side of the rifle. It was quite usual for submachine guns to have magazines on the side, but the bigger magazine with the heavier cartridges of a rifle quite unbalanced. Also, the end of the FG 42 rose into the air quite quickly when it was being fired in automatic mode. This made accurate automatic fire difficult. It also meant that automatic fire was not very useful. The U.S. M14 rifle had problems similar to these.
The American M41 Johnson LMG has many things that are similar to the FG 42. Both of these had their magazines on the left side. They also fired from an open bolt in automatic mode and closed bolt in semi-automatic mode. Although there are some things that are similar, there is no evidence that the designers of one weapon copied the design of another.
The last known weapons that were based on the FG 42 are the Sturmgewehr 52 and M60 machine gun.
After around 2,000 FG 42s were made by Krieghoff, the manganese steel that many important parts were made from were moved away to be used for other things. This meant that the weapon had to be redesigned to use stamped steel. Soldiers using the FG 42 asked for many small changes to be made to the design. These changes can be seen on later FG 42s. The FG 42 also had a simple bayonet under the barrel. It was hidden by the bipod. In the later version of the FG 42, the bayonet was shortened. Before the update, it was . Afterwards, it changed to about .
Bioorganic chemistry
Bioorganic chemistry is a science that combines organic chemistry and biochemistry. Bioorganic chemistry expands organic chemistry towards biology. This differs from biochemistry, which studies biological processes using chemistry. When investigating enzymes and cofactors, bioorganic chemistry overlaps bioinorganic chemistry.
Biophysical organic chemistry is a term used when attempting to describe intimate details of molecular recognition by bioorganic chemistry.
Bioorganic chemistry is that branch of life science, which deals with the study of biological processes using chemical methods.
Carbocation
A carbocation is an ion with a positively-charged carbon atom. The charged carbon atom in a carbocation is a "sextet" (that is, it has only six electrons in its outer valence shell instead of eight valence electrons.) Carbon atoms with eight valence elections have the maximum stability (octet rule). Therefore, carbocations are often reactive, seeking to fill the octet of valence electrons as well as regain a neutral charge. Logic would say that carbocation have sp hybridization with an empty sp orbital giving positive charge. However, the reactivity of a carbocation more closely resembles sp hybridization with a trigonal planar molecular geometry.
A carbocation was previously often called a "carbonium ion" but chemists question the exact meaning. In present-day chemistry, a carbocation is any positively charged carbon atom. Two special types have been suggested: carbenium ions are trivalent and carbonium ions are pentavalent or hexavalent. University level textbooks only discuss carbocations as if they are carbenium ions, or discuss carbocations with a fleeting reference to the older phrase of carbonium ion or carbenium and carbonium ions. One textbook to this day stays with the older name of carbonium ion for carbenium ion and reserves the phrase "hypervalent carbenium ion" for CH.
In 1891, G. Merling reported that he added bromine to tropylidene (cycloheptatriene) and then heated the product to obtain a crystalline, water soluble material, . He did not suggest a structure for it; however Doering and Knox convincingly showed that it was tropylium (cycloheptatrienylium) bromide. This ion is predicted to be aromatic by the Hückel Rule.