The following information is a guide to the presentation of experimental data, including appropriate formats for citation.
Yield should be presented in parentheses after the compound name (or its equivalent). Weight and percentage should be separated by a comma – for example, the lactone (7.1 g, 56%).
The melting point should be presented in the form mp 75 °C (from EtOH) - that is, the crystallisation solvent in parentheses. If an identical mixed melting point is to be recorded, the form mp and mixed mp 75 °C is appropriate.
The units should be stated in the preamble to the Experimental section – for example, [α]D values are given in 10−1 deg cm2 g−1. This should be shown in the form [α]D 22–22.5 (c 0.95 in EtOH) – that is, concentration and solvent in parentheses.
Given in the form nD22 1.653.
For the presentation of elemental analyses, both forms (Found: C, 63.1; H, 5.4. C13H13NO4requires C, 63.2; H, 5.3%) and (Found: C, 62.95; H, 5.4. Calc. for C13H13NO4: C, 63.2; H, 5.3%) are acceptable. Analyses are normally quoted to the nearest 0.1%, but a 5 in the second place of decimals is retained.
If a molecular weight is to be included, the appropriate form is: [Found: C, 63.1; H, 5.4%; M (mass spectrum), 352 (or simply M+, 352). C13H13NO4 requires C, 63.2; H, 5.3%; M, 352].
We encourage authors to provide instrumental details and the chromatograms of the performed measurements in the Supplementary Information where possible.
These should be given in the form λmax(EtOH)/nm 228 (ε/dm3 mol-1 cm-1 40 900), 262 (19 200) and 302 (11 500). Inflections and shoulders are specified as 228infl or 262sh. Alternatively the following form may be used: λmax (EtOH)/nm 228, 262 and 302 (ε/dm3 mol-1 cm-1 40 900, 19 200 and 11 500); log ε may be quoted instead of ε.
IR absorption should be presented as follows: νmax/cm-1 3460 and 3330 (NH), 2200 (conj. CN), 1650 (CO) and 1620 (CN). The type of signal (s, w, vs, br) can be indicated by appended letters (for example 1760vs).
For all NMR spectra δ values should be used, with the nucleus indicated by subscript if necessary (for example, δH, δC). A statement specifying the units of the coupling constants should be given in the preamble to the Experimental section – for example, J values are given in Hz. Instrument frequency, solvent, and standard should be specified. For example: δH(100 MHz; CDCl3; Me4Si) 2.3 (3 H, s, Me), 2.5 (3 H, s, COMe), 3.16 (3 H, s, NMe) and 7.3–7.6 (5 H, m, Ph).
A broad signal may be denoted by br, such as 2.43 (1 H, br s, NH). Order of citation in parentheses: (i) number of equivalent nuclei (by integration), (ii) multiplicity (s, d, t, q), (iii) coupling constant – for example, J1,2 2, JAB 4, (iv) assignment; italicisation can be used to specify the nuclei concerned (for example, CH3CH2). The proton attached to C-6 may be designated C(6)H or 6-H; the methyl attached to C-6, 6-Me or C(6)Me.
Mutually coupled protons in 1H NMR spectra should be quoted with precisely matching J values, in order to assist thorough interpretation. In instances of any ambiguities when taking readings from computer printouts, mean J values should be quoted, rounded to the nearest decimal point.
Mass spectrometry data
Mass spectrometry data should be given in the form: m/z 183 (M+, 41%), 168 (38), 154 (9), 138 (31) etc. The molecular ion may be specified as shown if desired. Relative intensities should be shown in parentheses (% only included once). Other assignments may be included in the form m/z 152 (33, M − CH3CONH2). Metastable peaks may be listed as: M* 160 (189→174), 147 (176→161), etc. The type of spectrum (field desorption, electron impact, etc.) should be indicated. Exact masses quoted for identification purposes should be accurate to within 5 ppm (EI and CI) or 10 ppm (FAB or LSIMS).