Comma
➤ Use a comma before, but not after, the coordinating conjunctions “and”, “or”, “nor”, “but”, “yet”, “for”, and “so” connecting two or more main clauses (complete thoughts).
Toluene and hexane were purified by standard procedures, and benzene was redistilled from calcium hydride.
The role of organic templates in zeolite synthesis has been studied extensively, but no general principles have been delineated.
Supported metals are among the most important industrial catalysts, yet only a few have been studied thoroughly.
No dielectric constants are available for concentrated acids, so it is difficult to give a quantitative explanation for the results.
➤ Use a comma after a subordinate clause that precedes the main clause in a complex sentence.
Although 40 different P450 enzymes have been identified, only six are responsible for the processing of carcinogens.
Since the institute opened, plant breeders have developed three new prototypes.
Because the gene and the molecular marker are so close on the chromosome, they segregate together in the progeny.
➤ Use a comma after most introductory words and phrases.
However, the public is being inundated with stories about cancer-causing chemicals.
Therefore, the type of organic solvent used is an important factor in lipasecatalyzed enzymatic synthesis.
After 3 months, the plants grown under phosphorus-deficient conditions were evaluated.
Thus, their motion is the result of the rotation of ferromagnetic domains.
On cooling, a crystalline phase may develop in coexistence with an amorphous phase.
➤ Use a comma before the coordinating conjunction in a series of words, phrases, or clauses of equal rank containing three or more items. (This comma is called the serial comma.)
Water, sodium hydroxide, and ammonia were the solvents.
The red needles were collected, washed with toluene, and dried in a vacuum desiccator.
The compound does not add bromine, undergo polymerization by the Diels– Alder reaction, or react with electrophiles.
➤ In compound sentences containing coordinating conjunctions, the clause following the conjunction is punctuated as if it were alone.
The reaction proceeds smoothly, and by use of appropriate reagents, the yields will be enhanced.
The compounds were separated, and after the filters had been washed, the experiments were completed.
➤ Do not use a comma to separate a verb from its subject, its object, or its predicate noun.
INCORRECT
The addition of substituted silanes to carbon–carbon double bonds, has been studied extensively.
CORRECT
The addition of substituted silanes to carbon–carbon double bonds has been studied extensively.
INCORRECT
The disciplines described in the brochure include, materials science, biotechnology, and environmental chemistry.
CORRECT
The disciplines described in the brochure include materials science, biotechnology, and environmental chemistry.
INCORRECT
The solvents used in this study were, cyclohexane, methanol, n-pentane, and toluene.
CORRECT
The solvents used in this study were cyclohexane, methanol, n-pentane, and toluene.
➤ Do not use a comma before the conjunction joining a compound predicate consisting of only two parts.
INCORRECT
The product distribution results were obtained in sodium hydroxide, and are listed in Table 10.
CORRECT
The product distribution results were obtained in sodium hydroxide and are listed in Table 10.
➤ Use commas to separate items in a series that contains another series in parentheses already separated by commas.
The structure was confirmed with spectroscopy (1H NMR, UV, and IR), highresolution mass spectrometry, and elemental analysis.
➤ Use a comma between two or more adjectives preceding a noun only if you can reverse the order of the adjectives without losing meaning. If you can insert the word “and”, the comma is correct.
The intense, broad signals of the two groups confirmed their location.
The broad, intense signals of the two groups confirmed their location.
Sample preparation is a repetitious, labor-intensive task.
Sample preparation is a labor-intensive, repetitious task.
A powerful, versatile tool for particle sizing is quasi-elastic light scattering.
A versatile, powerful tool for particle sizing is quasi-elastic light scattering.
But:
Polyethylene is an important industrial polymer.
The rapid intramolecular reaction course leads to ring formation.
The backbone dihedral angles were characterized by J couplings.
The local structural environment of the Mn cluster was determined.
➤ Use a comma before, but not after, the subordinating conjunction in a nonrestrictive clause.
INCORRECT
The bryopyran ring system is a unique requirement for anticancer activity whereas, the ester substituents influence the degree of cytotoxicity.
CORRECT
The bryopyran ring system is a unique requirement for anticancer activity, whereas the ester substituents influence the degree of cytotoxicity.
➤ Use commas to set off nonrestrictive phrases or clauses.
The products, which were produced at high temperatures, were unstable.
➤ Phrases introduced by “such as” or “including” can be restrictive (and thus not set off by commas) or nonrestrictive (and thus set off by commas).
Potassium compounds such as KCl are strong electrolytes; other potassium compounds are weak electrolytes.
Previously, we described a mathematical model including a description of chlorophyll degradation in foods.
Divalent metal ions, such as magnesium(II) and zinc(II), are located in the catalytic active sites of the enzymes.
Hydrogen-bonded complexes, including proton-bound dimers, are well-known species.
In the first two sentences, the phrases are restrictive because the sentences do not make their points without the phrases. In the third and fourth sentences, the phrases are nonrestrictive because the sentences can make their points without the phrases.
➤ An appositive is a noun that follows another noun and identifies or explains the meaning of the first noun.
My wife, Jeanne, is a biochemist at the National Institutes of Health.
My son James plays baseball, and my son John plays soccer.
An appositive is nonrestrictive (and therefore set off by commas) when it names the only possibility. In the first sentence, Jeanne is a nonrestrictive appositive. An appositive is restrictive (and therefore not set off by commas) when it points out one of two or more possibilities. In the second sentence, the names of the two sons are restrictive appositives.
➤ Use commas to set off the words “that is”, “namely”, and “for example” when they are followed by a word or list of words and not a clause. Also use a comma after the item or items being named. Use a comma after “i.e.” and “e.g.” in parenthetical expressions.
The new derivatives obtained with the simpler procedure, that is, reaction with organocuprates, were evaluated for antitumor activity.
Alkali metal derivatives of organic compounds exist as aggregates of ion pairs, namely, dimers, trimers, and tetramers, in solvents of low polarity.
Many antibiotics, for example, penicillins, cephalosporins, and vancomycin, interfere with bacterial peptidoglycan construction.
These oxides are more stable in organic solvents (e.g., ketones, esters, and ethers) than previously believed.
➤ Use commas to separate two reference citation numbers, but use an en dash (–) to express a range of three or more in sequence, whether they are superscripts or are on the line in parentheses. When they are superscripts, do not use a space after the comma.
Experimental investigations10,14,18–25^ concerned the relative importance of field and electronegativity effects.
Certain complexes of cobalt were reported (10, 11) to have catalytic effects on hydrolysis reactions.
Flash photolysis studies (3–7) demonstrated the formation of transient intermediate products such as triplet states.
➤ Use a comma before Jr. and Sr., but treat II and III according to the person’s preference. Within a sentence, always use a comma after Jr. and Sr., but use a comma after II and III only if they are preceded by a comma.
William M. Delaney, Jr.
Charles J. Smith, III John J. Alden II
William M. Delaney, Jr., was elected to the governing board.
Charles J. Smith, III, received a majority of the votes.
John J. Alden II did not run for office this year.
➤ Do not use a comma preceding “et al.” unless commas are needed for other reasons.
Saltzman et al.
Saltzman, M. J., et al.
Saltzman, Brown, et al.
➤ In dates, use a comma after the day, but not after the month when the day is not given.
When giving a complete date within a sentence, use a comma after the year as well.
On August 18, 1984, an extraordinary person was born.
➤ When a geographical location is named within a sentence and the name includes a comma, use a comma at the end of the name as well.
Iona College, in New Rochelle, New York, is the CEO’s alma mater.
The lead researcher, who obtained her education at the University of Calgary, Alberta, Canada, addressed the reporters’ questions.
➤ Use a comma to introduce quotations.
In the words of Pasteur, “Chance favors the prepared mind.” Pasteur said, “Chance favors the prepared mind.”
➤ Do not use a comma after a quotation that is the subject of the sentence.
“Chance favors the prepared mind” is a translation from the French. (The quotation is the subject of the sentence.)
Period
➤ Use a period at the end of a declarative sentence, but never in combination with any other punctuation marks.
He said, “Watch out!”
She asked, “May I go?”
➤ Do not use periods after most abbreviated units of measure, except when the abbreviation could be confused with a word (in. for inches, at. for atomic, no. for number).
➤ If a sentence ends with an abbreviation that includes a period, do not add another period.
She will return at 3 a.m.
➤ Use periods and spaces after initials in persons’ names.
J.-L. Gay Lussac J. E. Lennard-Jones M. S. Newman exception Use periods but no spaces when referring to authors of a paper in the acknowledgment paragraph of the paper.
R.C.McD. and C.R. thank Dr. Rose Allan for carefully reading the manuscript.
C.-C.Y., L.B.-P., N.-h.X., and S.Zh.O. are grateful for generous support from the university.
Semicolon
➤ Use a semicolon to separate independent clauses that are not joined by a conjunction.
All solvents were distilled from an appropriate drying agent; tetrahydrofuran and diethyl ether were also pretreated with activity I alumina.
➤ Use semicolons between items in a series of words, phrases, or data strings if one or more of the items already contain commas.
We thank Zachary Axelrod, University of Michigan, for spectral data; Caroline Fleissner, Harvard University, for helpful discussions; and the National Science Foundation for financial support (Grant XYZ 123456).
The product was dried under vacuum to give compound 2: yield 68%; IR 1991 m, 1896 s, sh, 1865 s cm–1; 1H NMR 0.36 ppm; 13C NMR 221.3, 8.1 ppm.
Figure 1. Cyclic voltammograms in dichloromethane: (a) compound 1, 23 °C; (b) compound 2, –40 °C; (c) compound 4, 23 °C.
Figure 6. Ru–H stretches in the IR spectrum of compound 5: ×, 298 K; +, 90 K.
This rule holds even if the only group containing the commas is the last in the series.
The compounds studied were methyl ethyl ketone; sodium benzoate; and acetic, benzoic, and cinnamic acids.
➤ Use a semicolon between independent clauses joined by conjunctive adverbs or transitional phrases such as “that is”, “however”, “therefore”, “hence”, “indeed”, “accordingly”, “besides”, and “thus”.
The rate at which bleaching occurred was dependent on cluster size; that is, the degradation of the mononuclear cluster was about 5 times faster than that of the tetranuclear cluster.
Many kinetic models have been investigated; however, the first-order reactions were studied most extensively.
The proposed intermediate is not easily accessible; therefore, the final product is observed initially.
The restriction of the rotational motions of the tert-butyl group gives rise to large entropy changes for the association reaction; hence, the covalent form is relatively easy to identify.
The efficiency of the cross-coupling depends on the nature of X in RX; thus, the reaction is performed at room temperature by slow addition of the ester.
➤ Do not use a semicolon between dependent and independent clauses.
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| INCORRECTThe activity on bromopyruvate was decreased; whereas, the activity on pyruvate was enhanced.CORRECTThe activity on bromopyruvate was decreased, whereas the activity on pyruvate was enhanced. |
Colon
➤ Use a colon to introduce a word, a phrase, a complete sentence, or several complete sentences that illustrate, clarify, or expand the information that precedes it. Capitalize the first word after a colon only if the colon introduces more than one complete sentence, a quotation, or a formal statement.
The electron density was studied for the ground state of three groups of molecules: (1) methane–methanol–carbon dioxide, (2) water–hydrogen peroxide, and (3) ferrous oxide–ferric oxide.
We now report a preliminary finding: no chemical shift changes were detected in the concentration range 0.1–10 M.
The following are our conclusions: Large-angle X-ray scattering studies give us an accurate picture of structures up to 9 Å. They do not allow the specification of defects, such as random ruptures of the chains. The structural models defined are strongly supported by magnetic measurements.
➤ In figure captions, use a colon to introduce explanations of symbols or other aspects of the figure.
Figure 1. Variable-temperature 1H NMR spectra of compound 12: top, 403 K; middle, 353 K; bottom, 298 K.
Figure 3. Brønsted-type plots for aminolysis in 1 M KCl at 25 °C: , 2-nitrophenyl acetate; , 3-chlorobenzoic acid; , 2,6-dinitrobenzoic acid.
➤ Do not use a colon (or any punctuation) between a verb and its object or complement or between a preposition and its object.
INCORRECT
The rate constants for the reaction in increasing concentrations of sodium hydroxide are: 3.9, 4.1, 4.4, 4.6, and 4.9.
CORRECT
The rate constants for the reaction in increasing concentrations of sodium hydroxide are 3.9, 4.1, 4.4, 4.6, and 4.9.
INCORRECT
The thermal decomposition was investigated with: gas chromatography, BET surface areas, and X-ray powder diffraction.
CORRECT
The thermal decomposition was investigated with gas chromatography, BET surface areas, and X-ray powder diffraction.
INCORRECT
Transition-metal nitrides have many properties that make them suitable for industrial applications, including: high wear resistance, high decomposition temperature, and high microhardness.
CORRECT
Transition-metal nitrides have many properties that make them suitable for industrial applications, including high wear resistance, high decomposition temperature, and high microhardness.
➤ Use either a colon or a slash to represent a ratio, but not an en dash. Use either a slash or an en dash between components of a mixture, but not a colon.
dissolved in 5:1 glycerin/water
dissolved in 5:1 glycerin–water
the metal/ligand (1:1) reaction mixture
the metal–ligand (1:1) reaction mixture
the metal–ligand (1/1) reaction mixture
the methane/oxygen/argon (1/50/450) matrix
the methane/oxygen/argon (1:50:450) matrix
Quotation Marks
Location of closing quotation marks with respect to other punctuation is a style point in which ACS differs from other authorities. In 1978, ACS questioned the traditional practice and recommended a deviation: logical placement. Thus, if the punctuation is part of the quotation, then it should be within the quotation marks; if the punctuation is not part of the quotation, the writer should not mislead the reader by implying that it is.
➤ Place closing quotation marks before all punctuation that is not part of the original quotation. Place them after all punctuation that is part of the quotation.
The sample solution was stirred briefly with a magnetic “flea”.
Ralph Waldo Emerson said, “The reward of a thing well done is to have done it.”
➤ Use quotation marks around words used in a new sense or words not used literally, but only the first time they appear in text.
Plastocyanin is a soluble “blue” copper protein.
The integrated intensity of each diagonal in the spectrum is proportional to a “mixing coefficient”.
The “electron-deficient” cations are, in fact, well-established intermediates.
➤ Use quotation marks to enclose the titles of uniquely named parts and sections of a book or a paper.
A complete description of the oils is given in the section “Flavonoids in Citrus Peel Oils”, and other references are listed in the bibliography.
But:
The preface describes the complexity of the problem.
➤ Use quotation marks to enclose short direct quotations (up to three sentences).
In the book Megatrends, Naisbitt concludes, “We are moving from the specialist who is soon obsolete to the generalist who can adapt.”
➤ Use a narrower column width (that is, indented on both sides) for longer quotations (extracts) of 50 words or more. Do not use quotation marks.
Everything is made of atoms. That is the key hypothesis. The most important hypothesis in all of biology, for example, is that everything that animals do, atoms do. In other words, there is nothing that living things do that cannot be understood from the point of view that they are made of atoms acting according to the laws of physics.
—Richard Phillips Feynman
However, this convention does not apply in an article quoting someone who has been interviewed. In such cases, quoted text need not be differentiated by column width, and quotation marks should be used.
➤ Use single quotation marks only when they are within double quotation marks.
He said, “You should read the article ‘Fullerenes Gain Nobel Stature’ in the January 6, 1997, issue of Chemical & Engineering News.”
Parentheses
Parenthetical expressions contain information that is subsidiary to the point of the sentence. The sentence does not depend on the information within the parentheses.
➤ Use parentheses for parenthetical expressions that clarify, identify, or illustrate and that direct the reader.
The total amount (10 mg) was recovered by modification of the procedure.
The final step (washing) also was performed under a hood.
The curve (Figure 2) obeys the Beer–Lambert law.
The results (Table 1) were consistently positive.
Only 15 samples (or 20%) were analyzed.
➤ Punctuate after, not before, parenthetical expressions.
INCORRECT
Compound 1, (7 mg) obtained by typical workup methods, was used without further purification.
CORRECT
Compound 1 (7 mg), obtained by typical workup methods, was used without further purification.
➤ If a parenthetical sentence is within another sentence, do not use a final period within the closing parenthesis, and do not start the parenthetical sentence with a capital letter.
Our results (the spectra are shown in Figure 5) justified our conclusions.
Our results justified our conclusions (the spectra are shown in Figure 5).
➤ If a parenthetical sentence is not within another sentence, use a final period inside the closing parenthesis, and start the parenthetical sentence with a capital letter.
A mechanism involving loss of a CH radical followed by rearrangement was proposed. (The reactions are shown in Scheme 1.)
➤ Use parentheses to enclose numerals in a list. Always use parentheses in pairs, not singly.
Three applications of this reaction are possible: (1) isomerization of sterically hindered aryl radicals, (2) enol–keto transformation, and (3) sigmatropic hydrogen shift.
➤ Use parentheses to identify the manufacturer of reagents and equipment.
cobalt chloride (Mallinckrodt) a pH meter with a glass electrode (Corning)
➤ Do not use parentheses when citing a reference number in narrative text. In such a case, the reference number is the point of the sentence, not subsidiary information, and thus not parenthetical.
INCORRECT
in ref (12), in (12)
CORRECT
in ref 12
➤ Use parentheses in mathematical expressions as discussed in Chapter 11 and in chemical nomenclature and notation as discussed in Chapters 12 and 13.
Square Brackets
➤ Use square brackets within quotation marks to indicate material that is not part of a direct quote.
In the words of Sir William Lawrence Bragg, “The important thing in science is not so much to obtain new facts as to discover new ways [italics added] of thinking about them.”
➤ Use square brackets to indicate concentration: [Ca^+^].
➤ Use square brackets in mathematical expressions as discussed in Chapter 11 and in chemical nomenclature and notation as discussed in Chapters 12 and 13.
Dashes
The shortest dash is the hyphen (-); the en dash (–) is longer; and the em dash (—) is the longest. Hyphens are discussed in the section on hyphenation in Chapter 10, starting on p 135.
En Dash
➤ Use an en dash to mean the equivalent of “and”, “to”, or “versus” in multiword concepts where the words are of equal weight.
acid–base titration
bromine–olefin complex
carbon–oxygen bond
cis–trans isomerization
cost–benefit analysis
dose–response relationship
ethanol–ether mixture
freeze–pump–thaw degassed
helix–coil transition
host–guest complexation
log–normal function
metal–ligand complex
metal–metal bonding
nickel–cadmium battery
oxidation–reduction potential
producer–user communication
pump–probe technique
red–black dichroic crystals
structure–activity relationship
structure–property relationship
temperature–time curve
vapor–liquid equilibrium
winter–fall maxima
0–t–∞ sequence
EXCEPTION Use a hyphen for color combinations such as blue-green. See Chapter 10, page 140.
➤ Use an en dash to mean “to” or “through” with a span of three or more numerals or other types of ranges.
12–20 months Figures 1–4 5–50 kg
sections 1b–1f parts C–E compounds A–I
Lyon and co-workers (23–26) Lyon and co-workers23a–d
EXCEPTION 1 When either one or both numbers are negative or include a symbol that modifies the number, use the word “to” or “through”, not the en dash.
–20 to +120 K –145 to –30 °C ≈50 to 60
10 to >600 mL <5 to 15 mg
EXCEPTION 2 Do not use an en dash when the word “from” or “between” is used.
from 500 to 600 mL (not from 500–600 mL)
between 7 and 10 days (not between 7–10 days)
➤ Use an en dash to link the names of two or more persons of equal importance used as a modifier.
Treatment of double surnames is covered in Chapter 10 (p 139).
- Bednorz–Müller theory
- Beer–Lambert law
- Bose–Einstein statistics
- Debye–Hückel theory
- Diels–Alder reaction
- Fermi–Dirac statistics
- Fischer–Tropsch effect
- Fisher–Johns hypothesis
- Flory–Huggins interaction
- Franck–Condon factor
- Friedel–Crafts reaction
- Geiger–Müller effect
- Henderson–Hasselbalch equation
- Jahn–Teller effect
- Lee–Yang–Parr method
- Lineweaver–Burk method
- Mark–Houwink plot
- Meerwein–Ponndorf theory
- Michaelis–Menten kinetics
- Stern–Volmer plot
- van’t Hoff–Le Bel theory
- Wolff–Kishner theory
- Young–Laplace equation
- Ziegler–Natta-type catalyst
➤ Use an en dash between components of a mixed solvent. (A slash can also be used.)
The melting point was unchanged after four crystallizations from hexane–benzene.
Em Dash
➤ Use em dashes to set off words that would be misunderstood without them.
INCORRECT
All three experimental parameters, temperature, time, and concentration, were strictly followed.
CORRECT
All three experimental parameters—temperature, time, and concentration—were strictly followed.
➤ Do not use em dashes to separate phrases or nonrestrictive clauses if another form of punctuation can be used.
INCORRECT
Knauth—not Stevens—obtained good correlation of results and calculations.
CORRECT
Knauth, not Stevens, obtained good correlation of results and calculations.
INCORRECT
The singly charged complexes—which constituted bands 1 and 3—liberated maleate anion upon decomposition.
CORRECT
The singly charged complexes, which constituted bands 1 and 3, liberated maleate anion upon decomposition.
Ellipsis Points
➤ Within a quotation, use three periods (points of ellipsis) to indicate deleted words or phrases. These three periods are in addition to other needed punctuation. Thus, if a period is already there, the result will be four periods.
No science is immune to the infection of politics and the corruption of power…. The time has come to consider how we might bring about a separation, as complete as possible, between Science and Government in all countries.
—Jacob Bronowski
➤ Do not begin or end a quotation with ellipsis points.
➤ Use ellipsis points where part of a series is omitted, when the pattern of the series is unambiguous.
a = 1, 2, 3, …
n = 2, 4, 6, …
x = 1, 3, 5, …, 15
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【参考】
- 《The ACS Style Guide》 3E
