유기화학의 어원과 용어

목차가 없는 도서입니다.

머리말

어원(語源)이란, 순수한 말로 말밑이라고도 하며, 어떤 말이 생겨서 이루어진 역사적인 근원, 또는 어떤 말이 생겨난 근원이라고 정의할 수 있다.
인간은 언어를 사용하여 사회집단의 구성원으로서, 문화에 대한 참여자로서 의사전달과 개인 간의 정보전달을 한다.
장자는 말하기를 언어란 뜻을 전하면 사라지는 것이라 하였다. 그 뜻을 명확히 알고 전달하기 위하여 인류가 맨 처음 무슨 근거에서, 왜 이 말을 사용하였는가 알 필요가 있다. 그래야 그 당시의 문화를 유추할 수 있고, 그 당시 문화에서 그 언어의 참 뜻을 유추할 수 있기 때문이다. 낱말 하나 밑에 문화의 전 체계가 달려있다. 그래서 언어는 살아있는 생명체이다.
유기화학을 가르치면서 교과서에 소개된 영어로 된 전문(專門) 낱말의 어원을 알고 나면, 그 뜻을 이해하기가 한결 쉬워짐을 알 수 있었다. 이것이 동기가 되어 이 책을 쓰기 시작하였다. 사전을 찾아 그 낱말의 어원을 알아내고, 그 낱말과 관련된 전문 용어를 해설하는 것으로, 저서라기보다는 편집하였다는 것이 적절한 표현일지도 모른다.
유기화학의 용어를 올바르게 이해한다는 것은 유기화학에 대한 기본 개념을 정확히 이해하여, 기초지식을 튼튼히 쌓고 나아가 교과서나 해당 논문을 이해하는 데 큰 도움이 되는 것은 새삼 강조할 필요가 없다. 유기화학을 배우거나 가르치는 자라면 유기화학에서 사용되는 낱말의 어원과 관련 용어를 찾는 수고를 하지 않으면 안 되기에, 그 번거러움을 덜어주고 싶어서 이 책을 저술하였다. 정확히 말하면 이 책은 유기화학에서 사용하는 영어로 된 용어의 어원과 관련용어의 사전인 셈이다.
이 책은 유기화학을 공부하는 학부학생, 대학원생과 유기화학을 직접 가르치는 교수에게 참고서로 자리매김하리라 확신한다. 아울러 과학도들이 어원을 알아가면서, 서양문명의 발원지인 그리스나 로마의 문명을 조금이라도 이해하는 과정에서 인문학적 소양을 만난다면 창의적인 생각이 필요한 과학도들에게 많은 보탬이 될 것이라 생각한다.
이 편저가 유기화학을 공부하는 학문 후속세대에게 이어지는 드넓은 다리가 되기를 바란다.
이 책을 쓸 수 있도록 생각을 일깨워 준, 의학어원론을 쓴 정 상우 교수에게 감사함을 전하고 싶다.

2014년 7월
이 왕근

absolute[bs?lu:t]: L. absolutus, pp of absolvere, freed, unrestricted. 절대적인, 온전한, 실제의.

absolute configuration: 절대배열. The spatial arrangement of the atoms of a chiral molecular entity (or group) and its stereochemical description e.g. R or S. Absolute configurations for a chiral molecule (in pure form) are most often obtained by X-ray crystallography. Alternative techniques are Optical rotatory dispersion[광학 회전 분산(능)], vibrational circular dichroism (진동 원편광 이색성) and the use of chiral shift reagents in proton NMR. When the absolute configuration is obtained the assignment of R or S is based on the Cahn-Ingold-Prelog priority rules. Absolute configurations are also relevant to characterization of crystals.

Until 1951 it was not possible to obtain the absolute configuration of chiral compounds. It was at some time decided that (+)-glyceraldehyde was the (R)-enantiomer. The configuration of other chiral compounds was then related to that of (+)-glyceraldehyde by sequences of chemical reactions. For example (+)-glyceraldehyde (1) was related to (-)-glyceric acid 2 (oxidation by mercury oxide) which in turn was related to (+)-isoserine 3 (nitric acid oxidation) and bromide 4 and (-)-lactic acid 5 (zinc reduction). Because the chemical transformations did not affect the asymmetric carbon atom, this sequence demonstrated that (-)-lactic acid was also a (R)-enantiomer. In 1951 Bijvoet for the first time used X-ray crystallography and a new property called anomalous dispersion to determine absolute configuration. The compound investigated was (+)-sodium rubidium tartrate and from its configuration (R,R). It was deduced that the original guess for (+)-glyceraldehyde was correct.

absorption[æbs:rp??n, -z:rp- /?b-]: L. absorbere, absorption, swallow up. 흡수, 흡광. A physical or chemical phenomenon or a process in which atoms, molecules, or ions enter some bulk phase - gas, liquid or solid material. This is a different process from adsorption, since molecules undergoing absorption are taken up by the volume, not by the surface (as in the case for adsorption). A more general term is "sorption", which covers absorption, adsorption and ion exchange. Absorption is basically where something takes in another substance.

acetal[s?tæl]: acetic acid + alcohol. 아세탈, 알데히드(케톤)와 알코올과의 화합물의 총칭. A molecule with two single bonded oxygens attached to the same carbon atom. Traditional usages distinguish ketal from acetal (whereas the ketal has two carbon-bonded R groups, the acetal has one carbon-bonded R group as H-). Current accepted terminology classifies ketals as a subset of acetals

Aldehyde to acetal conversion

Ketone to ketal conversion

acetic[?si:tik, ?st-]: L. acetum, vinegar. 식초의. 아세트산의.

acetic acid (= ethanoic acid): 식초산. An organic compound with the chemical formula CH3CO2H (also written as CH3COOH). It is a colourless liquid that when undiluted is also called glacial acetic acid(빙초산). Acetic acid is the main component of vinegar (apart from water), and has a distinctive sour taste and pungent smell. It is mainly produced as a precursor to polyvinylacetate and cellulose acetate. Although it is classified as a weak acid, concentrated acetic acid is corrosive, and attacks the skin. Acetic acid is one of the simplest carboxylic acids. It is an important chemical reagent and industrial chemical, mainly used in the production of cellulose acetate mainly for photographic film and polyvinyl acetate for wood glue, as well as synthetic fibres and fabrics. In households, diluted acetic acid is often used in descaling agents. In the food industry, acetic acid is used under the food additive code E260 as an acidity regulator and as a condiment(조미료, 양념).

acetylcholine[?si:tlkulin, æs?tl-]: 아세틸콜린(자율신경절의 주 신경 전달체). A neurotransmitter in both the peripheral nervous system (PNS, 말초신경계) and central nervous system (CNS, 중추신경계) in many organisms including humans. Acetylcholine is one of many neurotransmitters in the autonomic nervous system (ANS, 자율신경계) and the only neurotransmitter used in the motor division of the somatic(체세포의) nervous system. (Sensory neurons use glutamate and various peptides at their synapses.) Acetylcholine is also the principal neurotransmitter in all autonomic ganglia(신경절).

acetylcholinesterase (= cholinesterase): a family of enzymes that catalyze the hydrolysis of the neurotransmitter acetylcholine into choline and acetic acid, a reaction necessary to allow a cholinergic neuron to return to its resting state after activation.

acetyl CoA: an important molecule in metabolism, used in many biochemical reactions. Its main use is to convey the carbon atoms within the acetyl group to the citric acid cycle to be oxidized for energy production. In chemical structure, acetyl-CoA is the thioester between coenzyme A (a thiol) and acetic acid (an acyl group carrier). Acetyl-CoA is produced during the second step of aerobic cellular respiration, pyruvate decarboxylation, which occurs in the matrix of the mitochondria. Acetyl-CoA then enters the citric acid cycle. Acetyl-CoA is also an important component in the biogenic synthesis of the neurotransmitter acetylcholine. Choline, in combination with Acetyl-CoA, is catalyzed by the enzyme choline acetyltransferase to produce acetylcholine and a coenzyme as byproduct.

acetylene[?st?lin]: mid 19th century. acetum, vinegar + -yl + -enos, one. 아세틸렌. Systematic name: ethyne. It is a hydrocarbon and the simplest alkyne. This colourless gas is widely used as a fuel and a chemical building block. It is unstable in pure form and thus is usually handled as a solution. As an alkyne, acetylene is unsaturated because its two carbon atoms are bonded together in a triple bond.

achiral[?kiral]: G. acheir (a, not + kheir, hand). 손이 아닌. Describe an object that is superposable on its mirror image.

achiral (not chiral) objects: objects that are identical to their mirror image.

acid[cid]: L. acere, acidus, acida, acidum, tasting sour or bitter, sharp-tongued. 신, 쓴, 혀에 예민한, 화학 (산, 산의 성질을 갖는). A substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger. Chemicals or substances having the property of an acid are said to be acidic. Common examples of acids include acetic acid (in vinegar), sulfuric acid (used in car batteries), and tartaric acid (used in baking). As these three examples show, acids can be solutions, liquids, or solids. Gases such as hydrogen chloride can be acids as well. Strong acids and some concentrated weak acids are corrosive, but there are exceptions such as carboranes (a cluster composed of boron and carbon atoms) and boric acid. There are three common definitions for acids: the Arrhenius definition, the Brønsted-Lowry definition, and the Lewis definition.
Arrhenius acids
The Swedish chemist Svante Arrhenius attributed the properties of acidity to hydrogen in 1884. An Arrhenius acid is a substance that increases the concentration of the hydronium ion, H3O+, when dissolved in water. This definition stems from the equilibrium dissociation of water into hydronium and hydroxide (OH?) ions:
H2O(l ) + H2O(l ) ? H3O+(aq) + OH?(aq)
In pure water the majority of molecules exist as H2O, but a small number of molecules are constantly dissociating and re-associating. Pure water is neutral with respect to acidity or basicity because the concentration of hydroxide ions is always equal to the concentration of hydronium ions. An Arrhenius base is a molecule which increases the concentration of the hydroxide ion when dissolved in water. Note that chemists often write H+(aq) and refer to the hydrogen ion when describing acid-base reactions but the free hydrogen nucleus, a proton, does not exist alone in water, it exists as the hydronium ion, H3O+.

Brønsted-Lowry acids
While the Arrhenius concept is useful for describing many reactions, it is also quite limited in its scope. In 1923 chemists Johannes Nicolaus Brønsted and Thomas Martin Lowry independently recognized that acid-base reactions involve the transfer of a proton. A Brønsted-Lowry acid (or simply Brønsted acid) is a species that donates a proton to a Brønsted-Lowry base. Brønsted-Lowry acid-base theory has several advantages over Arrhenius theory. Consider the following reactions of acetic acid (CH3COOH), the organic acid that gives vinegar its characteristic taste:

Both theories easily describe the first reaction: CH3COOH acts as an Arrhenius acid because it acts as a source of H3O+ when dissolved in water, and it acts as a Brønsted acid by donating a proton to water. In the second example CH3COOH undergoes the same transformation, in this case donating a proton to ammonia (NH3), but cannot be described using the Arrhenius definition of an acid because the reaction does not produce hydronium. Brønsted-Lowry theory can also be used to describe molecular compounds, whereas Arrhenius acids must be ionic compounds. Hydrogen chloride (HCl) and ammonia combine under several different conditions to form ammonium chloride, NH4Cl. In aqueous solution HCl behaves as hydrochloric acid and exists as hydronium and chloride ions. The following reactions illustrate the limitations of Arrhenius's definition:

1. H3O+(aq) + Cl?(aq) + NH3 → Cl?(aq) + NH4+(aq)
2. HCl(benzene) + NH3(benzene) → NH4Cl(s)
3. HCl(g) + NH3(g) → NH4Cl(s)

As with the acetic acid reactions, both definitions work for the first example, where water is the solvent and hydronium ion is formed. The next two reactions do not involve the formation of ions but are still proton transfer reactions. In the second reaction hydrogen chloride and ammonia (dissolved in benzene) react to form solid ammonium chloride in a benzene solvent and in the third gaseous HCl and NH3 combine to form the solid.

Lewis acids
A third concept was proposed in 1923 by Gilbert N. Lewis which includes reactions with acid-base characteristics that do not involve a proton transfer. A Lewis acid is a species that accepts a pair of electrons from another species; in other words, it is an electron pair acceptor. Brønsted acid-base reactions are proton transfer reactions while Lewis acid-base reactions are electron pair transfers. All Brønsted acids are also Lewis acids, but not all Lewis acids are Brønsted acids. Contrast the following reactions which could be described in terms of acid-base chemistry.

In the first reaction a fluoride ion, F?, gives up an electron pair to boron trifluoride to form the product tetrafluoroborate. Fluoride "loses" a pair of valence electrons because the electrons shared in the B ?F bond are located in the region of space between the two atomic nuclei and are therefore more distant from the fluoride nucleus than they are in the lone fluoride ion. BF3 is a Lewis acid because it accepts the electron pair from fluoride. This reaction cannot be described in terms of Brønsted theory because there is no proton transfer. The second reaction can be described using either theory. A proton is transferred from an unspecified Brønsted acid to ammonia, a Brønsted base; alternatively, ammonia acts as a Lewis base and transfers a lone pair of electrons to form a bond with a hydrogen ion. The species that gains the electron pair is the Lewis acid; for example, the oxygen atom in H3O+ gains a pair of electrons when one of the H ?O bonds is broken and the electrons shared in the bond become localized on oxygen. Depending on the context, a Lewis acid may also be described as an oxidizer or an electrophile.

acidity[?sid?ti]: L. aciditas, aciditatis. 산성, 산성도.

acrylic[?krilik]: L. acrolein (acer, acri-, pungent + ol(eum), oil + -in, suffix) + -yl, suffix + -ic, icus, denoting an element in a higher valency. 아크릴 산의. 자극성 오일.

acrylic acid (IUPAC: prop-2-enoic acid): an organic compound with the formula CH2=CHCO2H. It is the simplest unsaturated carboxylic acid, consisting of a vinyl group connected directly to a carboxylic acid terminus. This colorless liquid has a characteristic acrid or tart(sour) smell. It is miscible with water, alcohols, ethers, and chloroform. More than one billion kilograms are produced annually.