Table Of ContentNMR Basic Principles and Progress 14
Grundlagen und Fortschritte
Editors: P. Diehl E. Fluck R. Kosfeld
Editorial Board: S. Forsan S. Fujiwara
R. K. Harris C. L. Khetrapal
T. E. Lippmaa G. J. Martin A. Pines
F. H. A. Rummens B. L. Shapiro
Heinrich N6th
Bernd Wrackmeyer
Nuclear Magnetic
Resonance Spectroscopy
of Boron Compounds
With 96 Tables
Springer-Verlag
Berlin Heidelberg New York 1978
Professor Dr. Heinrich Noth
Dr. Bernd Wrackmeyer
Institut fur Anorganische Chemie
der Universitiit Mtinchen
Meiserstr. 1
D-8000 Mtinchen 2
ISBN-13: 978-3-642-66759-6 e-ISBN-13: 978-3-642-66757-2
DOl: 10.1007/978-3-642-66757-2
Library of Congress Cataloging in Publication Data. N oth, Heinrich, 1928.
Nuclear magnetic resonance spectroscopy of boron compounds. (NMR,
basic principles and progress; v. 14) Includes bibliographical references
and indexes. 1. Boron compounds-Spectra-Tables. 2. Nuclear magnetic
resonance spectroscopy-Tables. I. Wrackmeyer, Bernd, 1947·joint author.
II. Title. III. Series. QC 490.N2 vol.14 [QC 462.B 1 J 538.3s
[546'.671'2 J 77-14148
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© by Springer-Verlag Berlin Heidelberg 1978.
Softcover reprint of the hardcover 1s t edition 1978
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2152/3140-543210
Preface
The revolutionary impetus of the NMR methods in organic chemistry has parallels in
the field of boron chemistry. lIB NMR spectroscopy provided a basis for the elucida
tion of structures and reactions of the boron hydrides. However, although many studies
have been carried out with the higher boranes, carboranes, metalloboranes, etc., and
although certain patterns have emerged, the correlation between the observed chemical
shift and the assigned structural unit is still not fully understood. Therefore, predictions
in this area are still rather limited, and semiquantitative interpretations are not yet pos
sible. Several years ago Eaton and Lipscomb sUpImarized the status in this field in their
book "NMR Studies of Boron Hydrides and Related Compounds" and a plethora of
new data has accumulated since then. The book also contained material on simple bo
rane derivatives, but they were not discussed in any detail. On the other hand many
systematic studies, both synthetic and spectroscopic, have been conducted on these
simple boron materials in the last decade. Thus a large amount of NMR information is
available, not only on lIB but also on 1 H, 1 3 C, and 14 N. However, this information
is widely scattered in the literature, and often the data are not discussed at all. It see
med appropriate, therefore, to collect these data and to present them in one volume.
In order to keep the presentation within a manageable size we had to restrict ourselves
to 11 B NMR data of compounds having boron atoms of coordination numbers 2, 3,
and4.
There are additional reasons for this limitation. Firstly, lIB NMR data in a series
of borane derivatives BXYZ indicate a linear relationship with 1T-charge densities at the
boron atom, and relations to other ground-state properties are indicated. Secondly,
there are linear correlations with 01 3 C and/or 014 N in isoelectronic or isosteric series
of boron, carbon, and nitrogen compounds, indicating similar substituent effects. Third
ly, bringing together many data might be helpful for a better comparison of the infor
mation available, leading to additional insight and stimulating new experiments.
The authors have tried to collect all 11 B NMR data of the classes of compounds
mentioned. Due to the ever increasing number of papers, however, some hardly acces
sible, they may have missed some and they are fully responsible on this point. They
welcome any additional and complementary information as well as comments and con
structive criticism concerning the discussion. On the other hand, the authors hope that
this compilation of data, organized in tables according to classes of compounds and to
"structure symbols," together with the discussion of the data will be helpful for all
those working in the field of borane and organoborane chemistry.
Munich, May 1977 Heinrich Nbth
Bernd Wrackmeyer
Contents
Chapter 1 Introduction and Scope . ............................. .
1.1. Application of liB NMR Spectroscopy. . . . . . . . . . . . . . . . . . . .. 1
1.1.1. Investigation of Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1
1.1.2. Investigation of Reactions ............................. 2
1.1.3. Application in Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3
1.2. Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3
Literature to Chapter 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4
Chapter 2 Nuclear Magnetic Properties of Boron. . . . . . . . . . . . . . . . . . . . .. 5
2.1. The Isotopes lOB, 11 B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5
2.2. Information from Boron NMR Data ..................... " 6
2.2.1. Chemical Shifts .................................... 6
2.2.2. Coupling Constants between Boron and Other Nuclei. . . . . . . . . . .. 6
2.2.3. Relaxation and Line Width. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6
2.2.4. Paramagnetic Compounds. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7
2.2.5. Exchange Processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7
2.3. Chemical Shifts .................................... 8
2.3.1. Theory of Chemical Shifts. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8
2.3.2. Empirical Correlations of 11 B Chemical Shifts. . . . . . . . . . . . . . .. 9
2.3.3. Semiempirical Calculations. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10
2.4. Spin-Spin Coupling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10
2.4.1. Theory of Spin-Spin Coupling ......................... " 10
2.4.2. Empirical and Semiempirical Correlation of Coupling Constants
Je
1 1 BX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12
Literature to Chapter 2 .. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 13
Chapter 3 liB NMR of Two-Coordinate Boron ...................... 15
Chapter 4 liB Chemical Shifts of Three-Coordinate Boron . . . . . . . . . . . . . .. 16
4.1. Survey of Substituent Effects . . . . . . . . . . . . . . . . . . . . . . . . . .. 16
4.1.1. a-and1T-BondingEffects .............................. 16
4.1.2. Anisotropy Effects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18
4.1.3. Effects of Ring Size and Steric Hindrance. . . . . . . . . . . . . . . . . .. 18
4.2. Triorganylboranes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19
VIII Contents
4.2.1. Trialkylboranes .................................... 19
4.2.2. Carbon-Substituted Trialkylboranes . . . . . . . . . . . . . . . . . . . . . .. 19
4.2.3. Unsaturated Triorganylboranes-Site of Unsaturation Adjacent to
Boron ........................................... 20
4.3. Halogenoboranes ................................... 21
4.3.1. Trihalogenoboranes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 21
4.3.2. Halogeno( organyl)boranes . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 22
4.3.3. Pseudohalogenoboranes and Pseudohalogeno( organyl)boranes . . . . .. 23
4.4. Boranes with Boron-Oxygen Bonds ....................... 23
4.4.1. Esters of Boric Acid and Organylboric Acids . . . . . . . . . . . . . . . .. 23
4.4.2. Boroxines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 24
4.4.3. Halogeno( organyloxo) boranes and Halogenoorganyl( organyloxo)-
boranes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 25
4.5. Boranes with Boron-Sulfur Bonds ........................ 26
4.5.1. Tris( organylthio )boranes and Organyl( organylthio )boranes . . . . . . .. 26
4.5.2. Borthiines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 27
4.5.3. Organylthioboranes Containing B-C, B-O, B-Halogen Bonds . . . . .. 27
4.6. Boranes with Boron-Selenium Bonds. . . . . . . . . . . . . . . . . . . . . .. 28
4.7. Boranes with Boron-Nitrogen Bonds. . . . . . . . . . . . . . . . . . . . . .. 29
4.7.1. Monoaminoboranes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 29
4.7.1.l. Aminoorganylboranes . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . .. 29
4.7.1.2. Cyclic Monoamino( organyl)boranes . . . . . . . . . . . . . . . . . . . . . .. 30
4.7.1.3. B-Functional Monoaminoboranes. . . . . . . . . . . . . . . . . . . . . . . .. 32
4.7.1.4. N-Substituted Monoaminodiorganylboranes . . . . . . . . . . . . . . . . .. 34
4.7.1.5. B,N-Functional Monoaminoboranes . . . . . . . . . . . . . . . . . . . . . .. 35
4.7.2. Bis(amino)boranes .................................. 35
4.7.2.l. Bis(amino)organylboranes ............................. 36
4.7.2.2. B-Functional Bis(amino)boranes ......................... 36
4.7.2.3. N-Functional Bis(amino)boranes . . . . . . . . . . . . . . . . . . . . . . . .. 38
4.7.2.4. B,N-Functional Bis(amino)boranes . . . . . . . . . . . . . . . . . . . . . . .. 39
4.7.3. Tris(amino)boranes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 39
4.7.4. Diborylamines and Triborylamines . . . . . . . . . . . . . . . . . . . . . . .. 41
4.7.4.1. Bis(diorganylboryl)amines and Tris(diorganylboryl)amines . . . . . . .. 42
4.7.4.2. B-Substituted Diborylamines. . . . . . . . . . . . . . . . . . . . . . . . . . .. 43
4.7.5. Ketimino and Aldimino Boranes .. . . . . . . . . . . . . . . . . . . . . . .. 44
4.7.6. Hydrazino( organyl)boranes. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 45
4.7.7. Diazaboracycloalkanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 45
4.7.7.l. Diazaborolidines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 45
4.7.7.2. Diazaborinanes and Higher Homologues . . . . . . . . . . . . . . . . . . .. 47
4.7.8. Borazines ........................................ 48
4.7.9. Six-Membered Boron Nitrogen Heterocycles Derived from
Borazines Containing Heteroatoms Other than Carbon. . . . . . . . . .. 51
4.7.lO. BN Isoconjugate Cyclic Polyenes . . . . . . . . . . . . . . . . . . . . . . . .. 52
4.7.11. Boron Heterocycles Containing a Hydrazino Group. . . . . . . . . . . .. 55
4.7.11.1. 1 ,2,4,3,5-Triazadiborolidines. . . . . . . . . . . . . . . . . . . . . . . . . . .. 55
4.7.11.2. Hexahydro-Tetrazadiborines . . . . . . . . . . . . . . . . . . . . . . . . . . .. 57
Contents IX
4.7.11.3. Boron Heterocycles Containing a Hydrazino Group and Ring
Atoms Other than Boron. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 57
4.7.12. 1,2,3,4,5-Tetrazaborolines(2) ........................... 59
4.7.13. Four- and Eight-Membered BN Heterocycles . . . . . . . . . . . . . . . .. 60
4.8. Diboron and Poly boron Compounds. . . . . . . . . . . . . . . . . . . . . " 61
4.9. Boranes with Boron-Hydrogen Bonds . . . . . . . . . . . . . . . . . . . . .. 63
4.10. Boranes with Boron-Silicon, Boron-Germanium, Boron-Tin,
and Boron-Lead Bonds ............................... 64
Chapter 5 lIB NMR of Transition Metal Boron Compounds . . . . . . . . . . . . .. 66
Chapter 6 11 B NMR of Diborane and Derivatives . . . . . . . . . . . . . . . . . . . .. 70
6.1. Diborane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 70
6.2. Organyldiboranes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 71
6.3. p-Substituted Diboranes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 71
6.4. Heptahydrodiborates and p-Substituted Derivatives. . . . . . . . . . . .. 72
Chapter 7 11 B NMR of Tetracoordinate Boron ...................... , 74
7.1. Metal Tetrahydroborates .. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 74
7.1.1. Alkali Metal Tetrahydroborates . . . . . . . . . . . . . . . . . . . . . . . . .. 76
7.1.2. Alkaline Earth Metal Tetrahydroborates . . . . . . . . . . . . . . . . . . .. 76
7.1.3. Aluminium Tetrahydroborates. . . . . . . . . . . . . . . . . . . . . . . . . .. 77
7.1.4. Transition Metal Tetrahydroborates . . . . . . . . . . . . . . . . . . . . . .. 79
7.2. Substituted Metal Tetrahydroborates . . . . . . . . . . . . . . . . . . . . .. 81
7.3. Metal Borates MB~ and [BX4-n Y n] ...................... 82
7.3.1. Metal Tetraorganylborates . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 82
7.3.2. Metal Halogenoborates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 83
7.3.3. Metal Borates with Various Substituents . . . . . . . . . . . . . . . . . . .. 84
7.4. Donor-Acceptor Complexes . . . . . . . . . . . . . . . . . . . . . . . . . . .. 84
7.4.1. Survey of Donor-Acceptor Properties . . . . . . . . . . . . . . . . . . . . .. 84
7.4.2. Boron Adducts with Oxygen Donors ...................... 86
7.4.3. Boron Adducts with Sulfur and Selenium Donors. . . . . . . . . . . . .. 87
7.4.4. Boron Adducts with Nitrogen Donors. . . . . . . . . . . . . . . . . . . . .. 88
7.4.4.1. Boron Adducts with Tetracoordinate Nitrogen . . . . . . . . . . . . . . .. 88
7.4.4.2. Boron Adducts with Three-Coordinate Nitrogen . . . . . . . . . . . . . .. 90
7.4.4.3. Boron Adducts with Two-Coordinate Nitrogen. . . . . . . . . . . . . . .. 91
7.4.5. "Boronium" Salts [Bis(amine )dihydroboron loCations ........... 92
7.4.6. "Chelate Complexes". . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 93
7.4.7. Borane Adducts with Phosphorous Donors .................. 93
7.4.7.1. BH3 Adducts of Phosphines . . . . . . . . . . . . . . . . . . . . . . . . . . .. 94
7.4.7.2. Organylborane Phosphines . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 95
7.4.7.3. Trihalogenoborane Phosphines .......................... 96
7.4.7.4. Halogeno(hydrido )borane and Halogeno( organyl)borane Phosphines . 98
7.4.7.5. Phosphine Adducts of Mixed Substituted Boranes . . . . . . . . . . . . .. 98
7.4.7.6. Cyclic Phosphinoboranes . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 99
X Contents
7.4.8. Borane Adducts of Arsines and Stibines .................... 100
Je
Chapter 8 Spin"spin Coupling Constants n 1 BX) .................... 102
8.1. Spin-Spin Coupling Between Boron and Hydrogen ............. 102
8.2. Boron-Boron Coupling Constants ......................... 103
8.3. Coupling Constants of Boron and Group IV Elements ........... 103
8.3.1. Spin-Spin Coupling Between Boron and Carbon ............... 103
8.3.2. Spin-Spin Coupling Between Boron and Silicon, Tin, and Lead ..... 104
8.4. Spin-Spin Coupling Between Boron and Group V Elements ........ 104
8.4.1. Spin-Spin Coupling Between Boron and Nitrogen .............. 104
8.4.2. Spin-Spin Coupling Between Boron and Phosphorus ............ 104
8.5. Coupling Between Boron and Group VI Elements .............. 105
8.6. Coupling Between Boron and Fluorine ..................... 105
8.7. Spin-Spin Coupling Between Boron and Transition Metals ........ 106
Chapter 9 Tables of 11 B-NMR Data . . . . . . . . . . . . . . . ............... 109
9.1. Remarks on the Organization of the Tables .................. 109
9.2. List of Tables, Including Structural Symbols ................. 110
9.3. Tables ........................................... 115
9.4. CA Formula Index .................................. 402
References ............................................... 430
Author Index. . . . . . . . . . . . . . . . . . . . . ......................... 448
Subject Index ............................................. 458
List of Editors
Editors
Professor Dr. Peter Diehl, Physikalisches Institut der Universitat Basel, Klingelberg
straBe 82, CH4056 Basel
Professor Dr. Ekkehard Fluck, Institut flir Anorganische Chemie der Universitat
Stuttgart, Pfaffenwaldring 55, D-7000 Stuttgart 80
Professor Dr. Robert Kosfeld, Institut fUr Physikalische Chemie der Rhein.-Westf.
Technischen Hochschule Aachen, Tempelgraben 59, D-5100 Aachen
Editorial Board
Professor Sture Forsen, Department of Physical Chemistry, Chemical Centre,
University of Lund, P.O.B. 740, S-22007 Lund, Sweden
Professor Dr. Shizuo Fujiwara, Department of Chemistry, Faculty of Science,
The University of Tokyo, Bunkyo-Ku, Tokyo, Japan
Dr. R. K. Harris, School of Chemical Sciences, The University of East Anglia,
Norwich NR4 7TJ, Great Britain
Professor C. L. Khetrapal, Raman Research Institute, Bangalore-560006, India
Professor E. Lippmaa, Department of Physics, Institute of Cybernetics, Academy of
Sciences of the Estonian SSR, Lenini puiestee 10, Tallinn 200001, USSR
Professor G. J. Martin, Chimie Organique Physique, Universite de Nantes,
UER de Chimie, 38, Bd. Michelet, F44 Nantes, B.P. 1044
Professor A. Pines, Department of Chemistry, University of California, Berkeley,
CA 94720, USA
Professor Franz H. A. Rummens, Department of Chemistry, University of Regina,
Regina, Saskatchewan S4S OA2, Canada
Professor Bernard L. Shapiro, Department of Chemistry, Texas A and M University,
College Station, TX 77843, USA
Notice to the Reader
Literature references for Chapters 1 and 2 are placed at the end of each chapter.
These references are indicated by raised numbers.
However for Chapters 3-9 the literature cited is accumulated in Chapter 10 and
numbers in square brackets are used throughout to assign a specific paper. Thus
[74/3] refers to a paper which is quoted third place under the literature references
reported for 1974.
Numbers in brackets refer to compounds quoted in the tables. (23/LVI) indicates
the 23rd compound in Table LVI.
