《ORGANIC CRYSTALS AND MOLECULES》

Ⅰ．INTRODUCTION3

1．Scope of modern crystallography3

2．Impact of the new discoveries on chemistry4

3．Arrangement of the subject matter7

PART ONE:THE NATURE OF CRYSTALS;GEOMETRICAL ASPECTS11

Ⅱ．THE CRYSTAL AS A GEOMETRICAL FIGURE13

1．Definition of a crystal;directional properties13

2．Constancy of angles and rational indices14

3．Symmetry17

4．Limitation of symmetry possible in a crystal19

5．The 32 point groups applicable to crystallography21

Ⅲ．THE CRYSTAL AS A LATTICE STRUCTURE28

1．Early structure theories28

2．Lattices and nets31

3．Limitation of symmetry in a lattice33

4．The 14 Bravais lattices34

5．Generalised structure theory38

6．The 230 space groups40

7．The crystal molecule46

Ⅳ．THE INTIMATE STRUCTURE OF CRYSTALS;X-RAY DIFFRACTION51

1．The discovery of X-ray diffraction51

2．The Bragg law53

3．Crystal analysis by homogeneous X-rays;rotation photo-graphs57

4．Oscillation and moving film photographs60

5．The reciprocal lattice65

6．Interpretation of single crystal photographs68

7．Determination of space group72

8．Powder photographs and fibre photographs77

Ⅴ．THE STRUCTURE FACTOR AND CALCULATION OF ELECTRON DENSITY81

1．General considerations81

2．The geometrical structure factor82

3．Scattering by electrons and atoms86

4．Scattering by crystals89

5．Generalised definition of the structure factor92

6．Expression of electron density by Fourier series94

7．Fourier synthesis96

8．Computational methods101

8A．Digital operations102

8B．Analogue computers105

9．Refinement of atomic parameters109

9A．Resolving power and accuracy109

9B．Differential synthesis111

9C．Method of least squares114

9D．Method of steepest descents115

9E．Fo-Fc synthesis116

9F．Advantagesand limitations117

Ⅵ．THE PHASE PROBLEM AND METHODS OF SOLUTION119

1．The phase problem119

2．Relations between structure factors123

3．Vector representation of crystal structure127

3A．The F2 series of Patterson128

3B．The Harker synthesis130

4．Interpretation of vector distributions131

4A．Simple distributions132

4B．Periodic distributions and effect of symmetry134

4C．Solution of vector sets138

5．The Patterson ambiguities140

6．Phase-determining methods141

6A．Use of a heavy atom143

6B．Isomorphous replacement147

PART TWO:THE ANALYSIS OF SOME ORGANIC MOLECULAR STRUCTURES151

Ⅶ．FUNDAMENTAL STRUCTURES AND EARLY WORK ON ORGANIC CRYSTALS153

1．Fundamental structures153

1A．Diamond153

1B．Graphite157

2．Molecular crystals160

3．Long chain compounds165

4．Some complete structure determinations170

4A．Hexamethylene tetramine and the cyclohexane hexa-halides171

4B．Urea and thiourea174

4C．Hexamethylbenzene and durene176

Ⅷ．BOND LENGTH MEASUREMENTS IN CONDENSED RING HYDRO-CARBONS AND SOME RELATED STRUCTURES183

1．The naphthalene-anthracene series183

2．Chrysene and dibenzanthracene196

3．Pyrene,triphenylene,and perylene200

4．Coronene and benzperylene204

5．Ovalene(octabenzonaphthalene)208

6．Non-planar condensed ring hydrocarbons and some related structures211

7．Covalent radii215

Ⅸ．MOLECULAR ARRANGEMENT AND HYDROGEN-BONDED STRUC-TURES219

1．The grouping of molecules in crystals219

2．Van der Waals,or non-bonded,radii226

3．The hydrogen bond228

3A．Chemical aspects228

3B．Mechanism of hydrogen bond formation230

3C．Symmetrical and non-symmetrical bonds:the isotope effect233

4．Types of hydrogen bond237

4A．Oxygen oxygen239

4B．Nitrogen．．．oxygen241

4C．Nitrogen．．．nitrogen244

4D．Nitrogen．．．chlorine245

5．Molecular compounds:clathrates246

Ⅹ．APPLICATIONS TO COMPLEX AND PARTIALLY KNOWN CHEMI-CAL STRUCTURES256

1．Problems involved and methods available256

2．The steroids258

3．The phthalocyanines262

4．The tropolones and colchicine271

5．Strychnine277

6．Penicillin281

7．Other applications286

Ⅺ．MACROMOLECULES AND BIOLOGICAL APPLICATIONS:EVIDENCE FROM THE ELECTRON MICROSCOPE288

1．General survey288

2．Fibre structures292

2A．Synthetic fibres292

2B．Cellulose294

2C．Rubber and gutta-percha298

3．Fibrous proteins300

3A．Experimental evidence300

3B．Interpretation305

4．Globular proteins310

5．Crystalline viruses320

INDEX OF NAMES327

INDEX OF SUBJECTS333