Revival: Handbook of Phosphorus-31 Nuclear Magnetic Resonance Data (1990)

John C. Tebby

• Publisher: CRC Press
• Year: 2017
• ISBN:
  9781351362030
• Edition: 1
• Topic: Ciencias físicas
• Subtopic: Química analítica

* 18 tables of 31P NMR data * 22 bar charts of 31P NMR chemical shift trends * Covers all structural types * Discusses data on low coordination compounds, three coordinate-five valent compounds, and phosphoryl stabilized caranions * Provides chemical shifts for nearly 20, 000 organic and inorganic phosphorus compounds

Chapter 1

Use of the Handbook and General Trends

John C. Tebby

Scope and Objectives

The handbook aims to provide a compilation of phosphorus-31 chemical shifts of organophosphorus compounds which is as comprehensive as possible in the available space. Important coupling constants involving phosphorus are given but references to NMR data relating specifically to other nuclei are not included. Inevitably there has had to be some selection of the data since in 1987 it was estimated that there were over 40,000 items of ³¹P NMR data in the literature. Nevertheless, the Handbook contains all classes of nonmetallic compounds known at the time of compilation, covered with as large a variety of structure and stereochemistry as possible. Some metallic compounds have been included, notably when the metal is stabilizing an interesting structure and those compounds used as organic synthons. It has been our goal that each entry provides additional information not provided by other entries. Significant differences in chemical shift for otherwise similar structures was also a valid reason for inclusion of data in the Handbook. In most cases where the solvent and temperature were recorded they are also shown.

The data is organized systematically, primarily according to the atomic environment of the phosphorus nuclei and then according to molecular formula. This allows the retrieval of NMR data for a specific compound and, where that is not available, to locate data for a phosphorus atom with as similar an environment as possible. It is also possible to estimate the effects of any remaining structural differences by comparing other related data. In the first place, the data are categorized according to the coordination number of the phosphorus atom, and then, within each coordination state, they are organized according to recognized or well-defined classes. For example, the four coordinate compounds are divided into phosphonium salts, phosphates, phosphonates, phosphinates, phosphine oxides, etc. The sequence within each class is determined primarily by the atoms bound to phosphorus: the presence and size of rings and then the connectivities of the phosphorus-bound atoms follow. The final prioritizing factor is molecular formula. Details and examples of the sequencing rules are given in the following section.

The coordination number is taken as the number of strongly covalently bound atoms to phosphorus. The bonds may be single, double or treble. Ionic or weakly coordinated atoms are not counted.

Occasionally contributors to the Handbook have deviated slightly from these strict rules in order to collect together other important structural features. For example, the polyphos-phines and their oxides are of particular interest to coordination chemists and therefore they have been placed in separate subsections throughout Tables E and L, respectively. For these tables it may be necessary to search two sections in order to be sure that the nearest structure about phosphorus has been identified. When two or more different phosphorus atoms are part of one molecule, the NMR data of each phosphorus environment appear at the appropriate position in the tables. In order to assist the identification of a structure for a recorded chemical shift the data are also presented in the form of a series of bar charts in the final section of this chapter. There is a comparison of the range of chemical shifts for compounds in each of the main classes of compounds right across the six coordination states. The data are also further analyzed according to each table and for some cases for the main subsections. In these tables certain structural features are identified on the bar lines.

The tables may also be used to estimate and study specific structural effects. For example, the change in chemical shift caused by incorporating a phosphorus atom in a small ring may be estimated by seeking matching cyclic and acyclic compounds having identical P-bound atoms and connectivities. The effect of replacing one group X by another group Y may be estimated by seeking matches differing only in X and Y.

Several measures were taken in order to make the most efficient use of space. An extensive list of abbreviations was used for functional groups and commonly occurring substructures, as well as for stereochemistry and solvents. Data from references quoted for other tables are not always duplicated; such references are prefixed by the letter of the relevant table.

Structure Definition

The atoms covalently bound to phosphorus are defined either as a subheading, i.e., P-bound atoms = XXX at the start of a set of data, or they are Listed in the first column of the table depending on the frequency with which they are changing. The P-bound atoms are presented as a formula arranged in the usual Chemical Abstracts manner (i.e., C before H, and H before other elements listed in alphabetical order). The atoms are in their normal coordination state with respect to their group position in the periodic table, e.g., four coordinate for carbon and silicon, three coordinate for nitrogen and phosphorus, two coordinate for oxygen and sulfur, etc. except where indicated otherwise. Coordination states one lower than normal are indicated by a prime, e.g., C, N’, and O’ for carbon, nitrogen, and oxygen, respectively; whereas coordination states two lower than normal are identified by double primes, e.g., C” and N” for two and one coordinate carbon and nitrogen, respectively. Higher than normal valencies are indicated by the valency number shown as a superscript, e.g., N⁴, P⁴, and S⁴ for four coordinate nitrogen, phosphorus, and sulfur, respectively. Two or more P-bound atoms of the same element with different coordination states are placed in the order of decreasing coordination number. Thus the P-bound atom formula for methylphenylcyanophosphine is CC’C”. The coordination differences are also used in the definitions of the connectivities. This is discussed later.

The incorporation of the phosphorus atom in a cyclic structure is indicated by adding the size of the Ring or Rings either immediately after the P-bound atom formula, e.g., CC’₂/5 for 2-methylphosphole or immediately in front of the connectivities — in both cases separated by a slash. Phosphorus atoms in bicyclic and tricyclic structures are indicated in a similar manner, e.g., C’₃/6,6 for 1-phosphabarrelene P(CH=CH)3CH. The number of rings incorporating the phosphorus atom is determined by the number of bonds that must be cleaved in order to create an acyclic phosphorus group. When there is a choice of ring size the smallest is stated and the larger omitted, e.g., C₃/5 and not C₃/6 for P-methyl 2-phosphanorbornane.

The next stage of structure definition concerns the second sphere of atoms surrounding the phosphorus atom. The atoms connected to each P-bound atom are stated in sets of Connectivities which are listed in the same order as the sequence of atoms in the P-bound atom formula. For example, methylphenylcyanophosphine with P-bound atoms = CC’C” has connectivities H₃;C’₂;N” since there are three hydrogen atoms bound to the methyl carbon, two ortho three coordinate carbons connected to the quaternary carbon of the phenyl group and a one coordinate nitrogen atom connected to the cyano carbon atom. When, as in this example, the P-bound atoms are nonidentical the sets of connectivities are separated by semicolons.

On the other hand, when there are two or more identical P-bound atoms, e.g., C₃ for methylethyl(t-butyl)phosphine, the connectivities ...

Table of contents

• Cover Page
• Title Page
• Copyright Page
• Contents
• Chapter 1 Use of the Handbook and General Trends
• Chapter 2 31P NMR Data of One and Two Coordinate Phosphorus Compounds
• Chapter 2a 31P NMR Data of Alkali Metal Phosphides
• Chapter 3 31P NMR Data of Three Coordinate (λ3 σ3) Phosphorus Compounds Containing Phosphorus Bonds to Halogen
• Chapter 4 31P NMR Data of Three Coordinate (λ3 σ3) Phosphorus Compounds Containing Bonds to Chalcogenides (O, S, Se, Te) but No Bonds to Halogen
• Chapter 5 31P NMR Data of Three Coordinate (λ3 σ3) Phosphorus Compounds Containing Phosphorus Bonds to Group V Elements (N, P, As, Sb) but No Bonds to Halogensnor Chalcogenides
• Chapter 6 31P NMR Data of Three Coordinate (λ3 σ3) Phosphorus Compounds Containing Phosphorus Bonds to Group IV Elements and Hydrogen Only
• Chapter 7 Three Coordinate Five Valent (λ5, σ3) Compounds
• Chapter 8 31P NMR Data of Four Coordinate Phosphonium Salts and Betaines
• Chapter 9 31P NMR Data of Four Coordinate Phosphorus Compounds Containing a P=Ch Bond but No Bonds to H or Group IV Atoms
• Chapter 10 31P NMR Data of Four Coordinate Phosphorus Compounds Containing a P=Ch Bond and One or Two P-H Bonds
• Chapter 11 31P NMR Data of Four Coordinate Phosphorus Compounds Containing a P=Ch Bond and One P-C Bond
• Chapter 12 31P NMR Data of Four Coordinate Phosphorus Compounds Containing a P=Ch Bond and Two P-C Bonds
• Chapter 13 31P NMR Data of Four Coordinate Phosphorus Compounds Containing a P=Ch Bond and Three Bonds from Phosphorus to Group IV Atoms
• Chapter 14 31P NMR Data of Four Coordinate Phosphorus Compounds Containing a Formal Multiple Phosphorus Bond to a Group V Atom
• Chapter 15 31P NMR Data of Four Coordinate Phosphorus Compounds Containing a Formal Multiple Bond from Phosphorus to a Group IV Atom
• Chapter 16 31P NMR Data of Four Coordinate Phosphorus Compounds Containing a Formal Negatively Charged Atom a to Phosphorus
• Chapter 17 31P NMR Data of Phosphoranides
• Chapter 18 31P NMR Data of Five Coordinate (λ5 σ5) Phosphorus Compounds
• Chapter 19 31P NMR Data of Six Coordinate Phosphorus Compounds
• Index