Page 001
`
`O-I Glass, Inc.
`Exhibit 1042
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 001
`
`

`

`SOCIETY OF ~,GLASS TECHNOLOGx]
`Monographs on Glass Technology.
`Edited by Professor W. E. S. Turner, F.R.S.
`
`THE CONSTITUTION OF ~LASS
`
`A Symposium of Papers by" Various Authors
`
`,9z5 (Now out of Print)
`
`ANALYSIS OF (~LASS, REFRACTORY
`MATERIALS AND SILICATE SLAGS
`
`A Collection of Papers by Various Authors
`
`~9z9
`
`REFRACTORY BLOCKS FOR
`GLASS TANK FURNACES
`
`by Dr. J. H. Partridge
`
`’935 ~
`
`GLASS-TO-METAL SEALS
`
`by Dr. J. H. Partridge
`
`"949
`
`¯ COLOURED- GLASSES
`
`by Professor W. A.Weyl
`’95: ¯
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 002
`
`

`

`COLOURED ’GLASSES
`
`WOLDEMAR A...W. EYL
`Professor~ and Head of the Department, of IVlineral Technology,
`Pennsylvania State College
`
`" I~UBLISHED BY
`"THE ~.OCIETY OF GLASS TECHNOLOGY
`"~ EL~MFIELD", NORTHUMBERLAND ROAD,
`
`¯ SHEFFIELD, ~o
`~95~ .
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 003
`
`

`

`CONTENTS
`
`FOREWORD B~ PROFESSOR W. E. S. TURNER .
`
`¯ AUTHOR’S PREFACE
`
`PART I.
`THE CONSTITUTION OF COLOURED GLASSES.
`
`I. THE ORIGIN OF COLOUR I~ INORGANIC SUBSTANCES
`Inorganic Chromophores .
`The Influence of Solvation on Colou~
`The Influence of Adsorption . .
`The Influence of Temperature on Colour
`
`PAGE
`
`vii
`
`3
`3
`9
`12
`
`II. THE CONSTITUTION OF G~ss
`General Renew of the ~oblem
`Ions as the Buil~ng U~ts of Glasses
`The ~nciples ~ve~ng the Io~c Structure o~
`~s~ls and Glasses . . .
`The Atomic Structure of Silica Glass
`The Ato~c Structure of Binary and Ternary
`Silicate Glasses .
`30
`The Ato~c Struct~e of ~oric "O~de-Containing- - -
`33
`Glasses
`The Atone ~tmct~re of’Phosphate
`35
`The N61e of ~0~, BeO, gnO, PbO ~nd TiOa in
`Glasses
`
`17
`17
`22
`
`26.
`28
`
`36
`
`III.
`
`THE CONSTITUTION OF GLASS
`The Replacement of Oxygen by other Elements
`Sulphur and Selenium as Substitutes for Oxygen
`Halogen Ions as Substitutes for Oxygen
`
`44
`
`44
`- 46
`
`THE TER~S ACIDITY AND BASICITY IN RELATION
`- TO MODERN THEORY OF STRUCTURE
`
`THE C~,ASSIFICATION OF GLASSES ACCORDING TO
`TKEm CHRO~OPHORES
`Coloured Glasses with One Colouring Ion .
`.
`Coloured Glasses with Chromophore Groups
`Consisting of Two Ions .
`.
`.
`Coloured Glasses with Chromoph’ore Groups
`Consisting of Three Ions
`
`THE CONSTITUTION OF GLASS AS REVEALED BY
`COLOUR AND FLUORESCENCE INDICATORS
`The Determination of the State of Oxidation of
`a Glass by the Indicator Method
`xi
`
`52
`
`57
`59
`
`60
`
`62
`
`64
`
`64
`
`VI.
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 004
`
`

`

`xii
`
`The Determination of the Acidity and Basicity
`of a Qlass by the Indicator Method
`The Determination of the Co-ordination N’umbe~
`of an Ion .
`Indicators for the ~ner~l EleCtric ~ertu~batio~
`of an Ion . . .
`Fluorescence Indicators
`
`PAGE
`
`66
`
`70
`
`74
`80
`
`PART II.
`THE COLOURS OF GLASSES PRODUCED BY VARIOUS
`COLOURING IONS,
`
`89
`
`89
`
`91
`
`VII. THE COLOUI~S PRODUCED BY IRON
`,
`The Influence of the Iron Content on the
`Technology of a Glass ....
`General Discussion on Absorption, Transmission
`and Colour
`A. The Spectral AbSorptiOn of" Iron" Com’-
`pounds in Aqueous Solutions and
`Glasses ......
`B. The Blue Colour in Iron-containing Glasses
`C. Colourless Iron Complexes in Glasses .
`The ~]quilibrium between Di- and Tri-valent
`Iron in Glasses .....
`I01
`A. The Influence of Temperature and Time 102
`B. The Influence of the Iron Concentration .
`103
`C. The Influence of the Composition of the
`Glass
`.
`D. The Influenc’e of 5xidising a£d Rehucing
`Agents
`
`91
`95
`97
`
`108
`
`113
`
`VIII,
`
`THE COLOURS PRODUCED BY MANGANESE .
`Introduction
`.
`.
`.
`.
`The Nature of the Manganese Colour
`.
`.
`Reactions During the Melting of Manganese
`Glasses
`The Melting if ManganeSe Gl~sses .
`
`121
`121
`121
`
`127
`129
`
`IX. THE COLOURS PRODUCED BY CHROMIUM~
`Introduction ....
`.
`.
`The Colour of Chromium Compounds
`The Nature of the Chromium Colour in Glasses
`The Melting of Chromium Glasses
`Chromium Pink
`
`Xo
`
`XI.
`
`THE COLOURS PRODUCED BY VANADIUM
`Introduction
`The Chemistry of Vanadium Compounds
`Vanadium in Glass
`
`THE COLOURS PRODUCED BY COPPER
`Introduction .
`
`132
`132
`1~2
`138
`142
`144
`
`149
`149
`149
`151
`
`154
`!54
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 005
`
`

`

`The Chemistry of Copper
`The Colour of Cupric Ions
`Glasses
`The ReductiOn of’Cupric to’Cupr’ous I~ns
`Aqueous Solutions and Glasses
`The Properties of. Copper Glasses
`
`in Crystals
`
`aA SolUtions
`
`THE COLOURS PRODUCED BY COBALT
`Introduction
`The Colour of
`Cobalt
`Cobalt Pigments
`Cobalt Glasses
`~uence of Temperature---- on the" Col4ur of
`Cobalt Glasses . . ..
`-Cobalt Glasses as Pyrosols
`The Melting of Cobalt Glasses
`Influence of Infra-Red Absorption on
`th~
`Melting and Working Properties of Glasses
`
`Nickel
`
`Glasses, Crystals
`
`THE COI~OURS PRODUCED BY NICKEL
`Introduction
`The Colour of
`Solution
`THE CO~OURS PRODUCE~ ~
`Introduction
`The Chemistry of Orani~m Co’mpou~ds
`Uranium in Glass .
`THE COLOURS PRODUCED BY TITANIIYM, TUNGSTEN
`~ND MOI~YBDENUM
`I. Titanium
`II. Tungsten and l~Iolyb~lenun~
`
`XII.
`
`~III.
`
`XIV.
`
`XV.
`
`xiii
`
`155
`
`156
`
`161
`163
`168
`168
`170
`176
`179
`
`187
`188
`190
`
`191
`197
`197
`
`197
`.205
`2O5
`2O5
`2O6
`
`212
`212
`216
`
`THE COLOURS PRODUCED BY THE OXIDES OF THE
`R~RE-E~R~S ELEMENTS’ .
`Introduction
`The Absorption S’pectr~ of "Neod~miu~a anti
`Praseodymium .... 220
`Glasses Containing Ne~dymi’um ~nd Praseo-
`dymium ......
`Some Applications of Neodymium Glasses
`Cerium-Containing Glasses
`
`221
`226
`229
`
`218
`218
`
`PART IlL
`THE COLOURS OF GLASSES PRODUCED BY THE NON-
`METALLIC ELEMENTS: SULPHUR, SELENIUM, TEL-
`LURIUM, PHOSPHORUS AND CERTAIN OF THEIR
`COMPOUNDS,
`XVII. THE COLOURS PRODUCED .BY SU-LPti~I~ AND ITS
`COMPOUNDS . 237
`Historical Review of the So-called Carbon-Amber
`Glasses
`
`237
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 006
`
`

`

`CONTENTS.
`
`The Constitution and Colour of Polysulphide
`Glasses
`The Melting ~f Car~on-~mber’(Sulp~ur) ~lasse~
`The Blue Sulphur Glasses
`Glasses Containing the Sul~hidos" of
`Metals
`Equilibria between’ Suip~ides ~nd S’ilieat~s
`The Striking of Colour in Sulphide Glasses
`The Melting of Sulphide Glasses_ , .
`Special Sulphide Colours in Glasses . .
`The Melting of Cadmium ’Sulphide Glasses
`Antimony Ruby Gl~sses . .
`Miscellaneous other Sulphides in Glasses .
`GLAsses Co~ov~v ~Y S~.n~y~ AND
`Elementary Selenium . .
`The Nature of Selenium Pink
`Reactions during the Melting of Selenium Glasses
`The Melting of Selenium Pink Glasses
`Conclusions on the Use of Selenium in "Glass"
`making .
`
`Glasses Coloured b’y Pofyse e des.
`
`Iron Selenide Glasses ~ . .
`Selenium Ruby Glasses and the Nature ’of th~
`Colour
`The Melting ~f Sel~niumlRub~ Glasses .
`Selenium Black Glasses .
`
`XVIII.
`
`XIX. GLASSES COLOURED BY TEI~URIUM AND BY
`PHOSPHORUS
`I. Tellurium
`II. Phosphorus . .
`
`PART IV.
`THE COLOURS PRODUCED BY METAL ATOMS.
`
`FUNDAMENTAI~S ~ONCERNING TH~ REI~TION8~"
`BETWEEN ~ET~q AND GLASSES
`
`242
`252
`257
`
`26O
`261
`265
`268
`270
`274
`275
`279
`282
`282
`282
`287
`.295
`
`301
`303
`3O4
`
`308
`313
`323
`
`324
`324
`325
`
`The Formation of Metal Atoms in Glasses
`The Solubility of Metals and the Formation o~
`Pyrosols .....
`The Influence of Some Constituents on th~ Solu"
`bility of Metals in Fused Salts and Glasses_ 339
`The R61e of Tin Oxide in the Formation of Ruby
`Glasses
`:
`The RSle of Stannous Chloride in the Formation
`of Silver Mirrors
`XXI. THE CRYSTAt,+.TRAT~ON OF i~_ET~T~ FROM
`GLASS I~IE LT
`The Mobility and Diffusion Speed of Metal Atoms
`in Glasses .
`
`331
`331
`
`333
`
`343
`
`348
`
`352
`
`352
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 007
`
`

`

`CONTENTS.
`
`xv
`
`355
`
`360
`
`366
`
`Nucleus Formgtion and Crystal Growth .
`The Theory of Coagulation. yon Smoluehow:
`ski’s Equation
`T~ ABSORPTION OF LIGHT BY ~ETAI~
`Fundamentals Concerning the Absorptioil of
`366
`Light by Metals ~.
`369
`The Scattering of Light .
`The Effect of the Nature of th~ Dispersed’Phase-- "
`371
`on the Absorption of Light by Colloidal Metals
`375
`The Effect of Shape and Internal Structure
`380
`380
`381
`384
`388
`391
`
`~-XXIII.
`
`XXIV.
`
`XXV.
`
`GOLD IN GOLD-RUBY GLASSES .
`Historical Introduction .
`The Nature of the Ruby Colo~r
`The Melting of Gold-Ruby Glasses .
`The Striking of Gold-Ruby Glasses . .
`The Basic Types of Gold Dispersion in Glasses
`
`SILVER IN G~ssEs .
`Introduction
`The Chemistry of ~ilver "Glasses
`The Melting of Silver Glasses .
`The Colour of Silver Glasses
`
`THE SILVER-STAINING OF GI~ASSES
`Introduction
`The Fundamentals’of th~ Staining o~ Gla£ses b~
`Cementation
`The Effect of the Glass Composition on the Silver
`Stain
`
`401
`401
`401
`406
`4O6
`
`4O9
`4O9
`
`410
`
`418
`
`XXVI.
`
`COPPER IN COPPER-RUBY GLASSES (HEMoATINO~E
`
`AND COPPER AVENTURINE}
`Introduction
`The Nature of Col ur odue d
`421
`Copper
`. 423
`The Work of’P. El~ell
`The Melting of Copper-Ruby ~lasse~
`" 425
`The RSle of the Tin in Copper-Ruby GlaSses . 427
`428
`The R61e of the Copper in Copper-Ruby Glasses
`430
`The~Striking of Copper-Ruby Glasses
`
`420
`420
`
`XXVII. TH~ COYPER STAINING OF GLASSES
`
`433
`
`PART V.
`
`THE FLUORESCENCE, THERMOLIYMINESCENCE AND
`THE SOLARISATION OF GLASS.
`XXVIII. TH~ GENERAL THEORY OF FLUORESCENCE IN
`GLAssEs
`Introduction
`
`439
`439
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 008
`
`

`

`~ XXIX.
`
`XXX.
`XXXI.
`
`CONTEI~S.
`
`PAGB
`
`A oms
`
`447
`
`Fh~or~soent Glasses .
`
`453 ;
`
`Fluorescence
`
`MoleCules .
`Glasses Containin&Fluorescent Ions
`The Uses of Fluorescent Gl~asses
`
`THERMOLUMINESCENCE
`
`TH~ SOL~mSATION OF GI~SS~S
`Fluorescence and Photosensitivity .
`The History of Studies on Solarisation
`The Explanation of Solarisation
`The Control of Solarisation
`The Regeneration of Solarised’Glass’es
`The Solarisation Equilibrium . .
`Helpful Models for the Study of Solarisation m
`Glasses
`
`PRACTICAL APPLICATIONS OF PHOTOSENSITIVE
`GLASSES
`
`AUTHOR INDEX
`
`SUBJECT INDEX
`
`465
`491
`495
`497
`497
`498
`50O
`507
`508
`511
`
`513
`
`515
`
`522
`
`529
`
`NOTE ON TEMPERATURE SCALES.
`
`All temperatures recorded in the Monograph are
`on the Centigrade scale unless otherwise stated.
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 009
`
`

`

`CHAPTEI~ I.
`
`THE ORIGIN OF COLOUI~ IN INORGANIC
`SUBSTANCES.
`
`INORGANIC CHROMOPHORES.
`
`I>r order to explain satisfactorily why certain substances possess
`colour, two factors have to be taken into consideration, first, the
`natnre of the atoms involved, secondly,’the chemical and electrical
`forces acting between them.
`For inorganic compounds, the first factor seems to be the more
`important, whereas the second plays the predominant rSle in the
`colour formation of organic substances.
`In this monograph it is not possible to enter into a detailed dis-
`cussion of the r61e played by the electronic configuration and the
`spectroscopy of different ions, but the reader may be referred to
`the work ofK. Fajans * and of M: N. Saha.$ The fundamental con-
`ception of light absorption has not .yet reached the stage where it, can
`be applied to attacking practical colonr problems, or to the develop-
`meat of new pigments. We have to be satisfied with the mere
`fact that there are ions--those of the transition elements--which
`impart colour to solutions and crystalline compounds. It is not
`possible to draw a sharp demarcation line between coloured and
`colonrless elements. Very often one element forms both coloured
`and colonrless ions. Many elements which are colourless in one
`state of valency possess strong colour in another.
`1. J. Piccard and E. Thomas $ have suggested a classification of
`ions into three groups :--
`
`(1) Coloured ions like those of cobalt, nickel and chromium.
`(2) Latently coloured ions like those of arsenic, antimony,
`cadmium, iodine and sulphur. These elements form colourless
`ions, but possess a tendency to form col6ured compounds,
`such as CdS, HgI~, As~Sa.
`(3) Colourless ions like those of A1, Ba, Ca and the alkalies.
`
`So far as the r61e of chemical forces between the atoms is con-
`eerned, we are still far from a general theory as to how they affcct
`colour and light absorption. In the course of time certain rnles have
`
`¯ Naturwissenschafle~, 1923, 11, 167; Z. Eleklrochem., 1923, ~9, 495.
`"~ Nature, 1930, 1~5, 163 164.
`~. Helvetica Chim. Acta, 1923, 6, 1040 1043.
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 010
`
`

`

`4
`
`COLOURED GLASSES.
`
`been established. For simple organic compounds it is even possible,
`to a certain extent, to predict the colour from the structuralformula.
`For inorganic substances, however, there is no such possibility,
`even when the composition, the interlinkage of the atoms, and their
`arrangement in the lattice are known.
`The different chromophore theories which have been advanced by
`O. N. Witt,* H. Kauffmann,t W. Dilthey and R. Wizinger,:~ es-
`pecially for the understanding of the light absorption by aniline dyes,
`have a common nucleus even when they look entirely different and
`are based on v¢idely differing conceptions. No matter if these authors
`talk about double bonds between atoms, the splitting of valency,
`or of a single atom with unsaturated co-ordination, they all connect
`the origin of colour with the same phenomenon--namely, a field of
`force, chemical or electrical in nature, not fully saturated or
`balanced. Even in the simpl~ organic com. pounds, such as the hydro-
`carbons, an accumulation of these unsaturated atoms will gradu-
`ally lead to the development of absorption bands in the visible
`spectrum. In general, however, organic dyes do contain elements
`which occur in an unsaturated state, such as nitrogen and sulphur.
`Based on extensive observations, W. Biltz § laid down the following
`rule for correlating the valency and the colour of inorganic com-
`pounds :--
`" Complete saturation of the chemical or electrical valency, as
`well as strong binding forces, favour light transmission. Un-
`saturated valencies or weak bonds favour the absorption of light
`and deepen the colour. The extremes of both types are the alkali
`salts on the one side and the intermetallic compounds on the other.
`Deepening the colour means changing it from yellow to orange, red,
`purple, violet, blue, and finally to green. In those cases where the
`absorption is very intense, the substance may even have a metallic
`lustre."
`This rule applies to numerous inorganic compounds, and it may
`Serve not only to correlate certain colour phenomena, but also as a
`valuable guide in developing new colours and pigments. The
`exact meaning of the rule can best be demonstrated by a few typical
`examples.
`It is a well-known fact that the colour of those compounds which
`contain an element capable of two different valencies is much
`deeper than that of the two end members which make up the mixed
`compound. Long ago J. J. Berzelius pointed out that the deep
`
`* Ber., 1876, 9, 522; 1888, i~l, 321.
`~ Die V~lenzlehre, Stuttgart, 1922.
`~. J. pralct. Chem., 1928, 118, 321--348.
`
`§ Z. anorg. Chem., 1923, 127, 169--186.
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 011
`
`

`

`TI~E CO~STITUTIO~ OF COLOURED GLASSES.
`
`colour of the ink made from gall might be due to the formation of
`a double salt containing both the lower and the higher oxide of
`iron. He drew the analogy between it and the blue colour obtained
`from the complex cyanides ofiron. When A. Werner * made his study
`of the complex platinum compounds, he noticed that the colour was
`considerably deeper whenever the salt contained platinum in different
`states of oxidation. He assumed that the reason was similar to that
`underlying the deep colour of quinhydrone and of tungsten bronze.
`K. A. Hofmann, F. Resencheck and K. HSschele ~ made a
`detailed study of these relations, a~d found a whole group of com-
`pounds which are extremely strongly coloured by one element when
`present in two different states of valency. His discovery of the
`uranium-cerium-blue seemed to indicate that different elements
`might also cause this effect when the conditions allow an " oscil-
`lation " of the valencies. The following table (Table I) contains
`some characteristic examples.
`
`TABLE I.
`
`End member I. Mixed compound. End member II.
`dark yellow.
`red.
`yellow.
`KO3
`K~O~
`K~O3
`brown.
`black.
`RbOz
`,,
`Rb~Os
`Rb~O~
`orange.
`dark red.
`AuCls
`light yellow.
`AuC1
`Au~C14
`Hg(NO3)~ colourless.
`1-IgNO~’Hg(NO~)s yellow.
`HgNO~ colourless.
`,,
`T1Cls ¯
`T1CI~’3T1C1 ,,
`T1C1 ,,
`,,
`red.
`T1Br~
`T1Brs.3T1Br
`T1Br
`,,
`
`A c~esium-gold chloride of the formula CssAuIAun~C16 is black
`because it contains monovalent and trivalent gold ion. Cryst, allised
`(NH4)sSbBr6 and the corresponding rubidium salt are violet-black
`because the crystals do not contain Sb4+ as might be suggested by
`the formula, but alternating complexes of Sbs+ and Sb5+.
`¯ Salts of this type form deeply coloured crystals which can be
`obtained from weakly coloured solutions. In other cases strongly
`coloured complexes are formed even in solutions and glasses. The
`dark colour of Cu+ and Cu+ ÷ simultaneously present in a glass or in
`HC1 solution is a typical example.
`The deep colours obtained by partial reduction of molybdenum-,
`columbium- and tungsten-compounds belong to the same group.
`Dissociation frequently causes a colourless compound to change
`into intensely coloured radicals. The best-known examples are the
`derivatives of ethane which form radicals with trivalent and, there-
`fore, extremely unsaturated carbon atoms.
`
`(C~Hs)a~.(cid:128)--C~_(C~H~)a > 2(C~H~)~--C--
`Colourless. Yellow.
`
`* Z. anorg. Chem., "1896, 12, 46--54.
`~ Liebig’s Ann. Chem., 1905, 342, 364--374; Ber., 1915, 48, 20--28.
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 012
`
`

`

`COLOURED GLASSES.
`
`Whan the valency of the lead in its organometallic compounds is
`decreased, colour results, as in the following series :
`
`:Pb~---(C6~Is)4 colourless.
`~)b~(C6]7~5)3 yellow.
`Pbz(C~Hs)2 deep red.
`
`Even in cases where the valency stays unaltered, the light absorp-
`tion will be intensified when the valence forces are not uniformly
`distributed. This is the case with graphite, in which a strong
`interlinkage exists between th~ carbon atoms within the planes,
`but the planes are held together by only feeble forces. In contrast
`to the strong absorption by graphite, the diamond is colourless;
`for within its lattice the valencies or electrostatic forces are highly
`symmetrical. Some diamonds probably owe their dark colour not
`only to impurities, but also, and perhaps primarily, to imperfections
`in the crystal lattice. A comparison of the colours of compounds
`containing elements in the same state of valency shows that weak
`binding forces give strong colours and vice versa. The heat of
`formatior~ can be used as an approximate means to measure the bond
`strength. Many metals forming colourless oxides give brightly
`coloured sulphides. The same change in colour which accompanies
`the transition from the oxide to the sulphide (see Table XI) can also be
`noticed when 5hlorides are compared with bromides and iodides (see
`Table III).
`
`colourless. ¯
`Titanium dioxide
`,,
`Tin dioxide
`yellow.
`Lead oxide
`colourless.
`Arsenic trioxide
`Molybdenum dioxide blue.
`
`Titanium disulphide
`yellow.
`,,
`Tin disulphide
`black.
`Lead sulphide
`yellow.
`Arsenic trisulphide
`Molybdenum disulphide black.
`
`TABLE III.
`
`Compound:
`
`Chloride.
`
`Bromidel
`
`Iodide.
`
`colourless,
`........................
`Silver
`Mercuric .......................
`Lead ...........................
`,,
`Carbon ........................
`brown.
`Nickel ........................ yellowish-brown.
`light blue. green.
`Cobaltous .....................
`
`light yellow.
`colourless.
`,,
`
`yellow.
`yellow or red.
`yellow.
`red.
`black.
`
`Comparing compounds of different metals with one and the
`same element ’ such as sulphur, the same rule holds true. The
`sulphides of c~lcium, strontium, barium, magnesium and zinc,
`with heats of formation of more than 40 Cal., are colourless.
`Sulphides with medium heats of formation, like those of manganese
`and cadmium, are coloured, and those with very small heats of
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 013
`
`

`

`THE COI~STITUTIO~ 01~ COLOURED GLASSES.
`
`formation (3--24 Cal.) are black, as, for example, those of l~e, Co,
`Ni; Cu, Pb and Hg.
`Adding neutral molecules to a saturated conSpound might cause
`a splitting of valencies and, therefore, lead to intensifying the colour.
`This applies to the colour change which accompanies the formation
`of hydrates, ammines and addition products of the NO group with
`neutral salts..
`These examples might suffice to show that there are a great number
`of unrelated or only weakly related facts concerning the colours of
`inorganic materials. A worker in the field of coloured glasses needs
`some hypothesis as a guiding principle. The author has found in
`K. Fajans’ theory of the deformation and polarisation of ions a
`valuable guide. In the discussion of the ionic colonrs reference will
`repeatedly be made to Fajans’ concept which is here briefly outlined.
`~- more complete discussion can be found in his Baker Lectures.*
`The optical properties of an ion, in particular its light absorption
`and emission, are functions of its own electronic configuration and
`of its environment. The electric fields of neighbouring ions exert a
`polarising (deforming) influence on the electron orbits of the ab-
`sorption centre. The nature of its closest neighbours, their number
`(co-ordination number) and their geometrical arrangement in space
`(crystal symmetry) are equally important for its colour and fluores-
`cence. These are the three factors which are chiefly responsible for
`the difference in optical properties which exists between an ion in
`its gaseous state and the same ion in a condensed system. Through
`the polarising influence of the environment some electron transitions
`become more or less probable. In practically all cases the energy
`requirement for a certain transition is changed. As a result the
`light absorption and emission may be shifted either to longer or
`shorter wavelengths; certain bands characteristic of the gaseous
`state may not be found ff the ion is brought into an aqueous solution
`or into a crystal or a glass. On the other hand, the electron con-
`figurations of the ~ransition elements in their gaseous state do not
`permit absorption of visible light quanta, but their ions permit
`absorption under the mutual deforming influence of large and
`polarisable anions. In their liquid and crystalline state most
`compounds of copper, iron, nickel and manganese are coloured. The
`molar extinctions of these compounds are low in comparison with
`those of most organic dyestuffs. Nevertheless, the fact that they
`are coloured Proves that transitions which do not occur in the gaseous
`ions have become possible through the deforming influence of their
`environment.
`
`* K. Fajans, ~:hemical Forces and Optical Properties of Substances, McGraw-
`
`Hill Book Co., New York, 1931.
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 014
`
`

`

`~ The exact relations which exist between the electron transitions
`in a given atom.and the strength and orientation of its surrounding
`electric field are not yet fully established.
`Over a period of nearly twenty-five years, K. Fajans and his
`students have accumulated a vast amount of knowledge concerning
`the relations which exist between optical properties and chemical
`forces. In order to explore the change in the configuration of the
`outer electrons which takes place if two elements combine to form a
`chemical compound, K. Fajans studied the changes in molecular
`refractivity. Both optical and chemical properties of a substance
`depend to a ~najor extent upon the outer electrons. Chemical or
`electrical forces exerted by adjacent atoms influence the response
`of these outer electrons to the electro-magnetic field of light. The
`molecular refraction as a tool for studying chemical bonding offers an
`advantage over other optical properties in that it can be measured
`with great accuracy for many substances and can be expressed by
`one numerical value. The difficulties involved in correlating light
`absorption and emission with the chemical forces acting in simple
`inorganic compounds have prevented similar progress in this
`field.
`J. Meisenheimer * made the first attempt to explain the unusual
`colours of some inorganic compounds by the mutual deformation of
`ions as a result of compound formation. :He explained the yellow
`colour of lead iodide on this basis. The iodide ion is large, and
`therefore easily deformable. In combination with ions having
`complete outer electronic shells (noble gas ions) it does not possess
`light absorption in the visible region. Ions of the non-noble-gas
`type, even if they are colourless by themselves, such as 1)b2+ or Hg2+,
`produce coloured iodides. Phi2 is yellow; HgI2 is red. In this
`case, according to K. Fajans, compound formation consists not only
`of the electrostatic attraction of two rigid spheres having electric
`charges of opposite sign but involves the deformation of their outer
`electron orbits. Anions are larger than cations of the same atomic
`number. They are more easily deformed than cations because
`their outer electrons are farther away from the positive nucleus, and
`therefore less rigidly bound. The deformation of an anion in-
`creases with its size and is particularly strong ff it is exposed to the
`influence of cations of the non-noble-gas type. Thus, the cations
`of the transitional elements have a stronger polarising or deforming
`action than the group of alkali ions which have the structure of a
`rare-gas atom; namely, eight outer electrons. One can describe
`the polarising influence of a cation upon a large polarisable anion as
`its endeavour to " pull over " some of the electrons of the anion in
`¯ Z. physikal. Chem., 1921, 97, 304.
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 015
`
`

`

`THE CO~STITUTIO~ OF COLOURED GLASSES.
`
`order to complete its own shell to a stable octet. This tendency can
`lead ~o a complete removal of an electron from the anion.
`K. l~’ajans pointed out that in combination with F- or other
`anions of low polarisability, such as SOn2-, the cupric ion forms
`colourless compounds. CuC12, however, is yellow, and CuBr2 is deep
`brown.’ With increasing size ofthe anion, the mutual deformation
`produces a light absorption which is not possible within the undis-
`turbed gaseous ions. Proceeding to the still larger iodine ion, one
`finds that the Cu2+ actually pulls over an electron from the iodine.
`As the result, cupric iodide is not stable but decomposes into cuprous
`iodide and a neutral iodine atom.
`
`CuI~, > CuI + I
`A similar deepening ~f the colour can be found in other metal
`halides if the fluorine ion is replaced by anions which are larger and
`more polarisable. The colours of the nickel halides furnish other
`examples. Thus :
`
`NiF~
`fain~
`yellow
`
`NiC12
`yellow
`brown
`
`NiBr2
`dark
`brown
`
`NiI2
`black
`
`Ions in s.olution are exposed to the electric fields of the surrounding
`solvent molecules. This interaction between solvent and solute is
`Galled solvation. In many cases it is possible and practical to treat
`this interaction as from a merely electrostatic point of view. In
`other cases, however, it is necessary to consider the formation of
`new molecules or compounds.
`In the case of elementary iodine, the effect of solvents on the light
`absorption can be easily demonstrated and used as a model for similar
`cases. It has been known for a long time that iodine dissolved in
`different organic solventsproduces different colours. Without
`going into all the different theories developed foi explaining these
`colour changes, the two most probable may be referred to. The
`one explains the change as the result of solvation and the
`electric stray fields of the solvent molecules. The other prefers
`to regard the results observed as arising from the formation of
`well-defined molecules or complexes of stoichiometric composition.
`Both theories are based on measurements of vapour pressure,
`depression of freezing point and dielectric properties. The light
`absorption of iodine in different solvents has been studied by E.
`Kreidl * in the laboratory of the author. It was the aim of this
`
`¯ See W. A. Weyl, Ver6ffentl. Kaiser Wilhelm Inst.fiir Silikatforschung, 1935,
`7, 167--203.
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 016
`
`

`

`10
`
`COLOURED GLASSES.
`
`invdstigation to find out whether or not light-absorption measure.
`merits would lead to a decision between the-two most probable
`theories. From earlier experience it was expected that solvation
`alone without the formation of chemical compounds would change
`the spectrum in a two-fold way :
`
`(1) By broadening due to general perturbation.
`(2) By a shift of the absorption band towards the shorter
`wavelengths.
`
`:Formation of a new compound, on the other hand, would lead
`to a new chromophore and, therefore, to a new type of absorption
`spectrum. The minimum amount of solvation and perturbation
`was to be expected when hexane, a non-l~olar solvent, was used.
`In a solution of iodine in hexane, increasing amounts of the non-
`polar were gradually replaced by polar molecules. The investiga-
`tion of several such binary systems gave two different groups of
`curves which could be attributed to two different processes, sol-
`vation and compound formation. The system hexane-benzene
`(Fig. 1) represents the first type in which the light absorption is
`affected by a solvation process only. The absorption band increases
`somewhat in height and is shifted towards the shorter wavelengths.
`This shift is more pronounced for the short than for the long wave
`edge, so that a broadening of the absorption band results. Com-
`parison between benzene and toluene (Fig. 2) indicates that the latter
`has the stronger effect.
`A completely different group of curves is obtained when hexane
`is gradually replaced by ether (Fig. 3) or alcohol (Fig. 4). Here the
`absorption spectrum indicates that the amount of free iodine
`decreases and that a new compound is formed which causes a new
`absorption band to appear. Comparing the effect of alcohol and
`ether, it can be seen that the former is more effective, for only small
`amounts are necessary to decrease the height of the absorption
`band characteristic of the free iodine.
`Similar changes in the light absorption can be found when ions
`of the transition ele~nents are compared in diluted and concentrated
`solutions or in glasses of different composition. Using organic
`dyes, F. Bandow * showed that the shift of absorption by changing
`from water to sulphuric acid or to phosphoric acid as a solute is
`not so much a characteristic effect of these acids; it can better be
`explained as resulting from the withdrawal of water. The dehydrat-
`ing effect of both acids can be measured by their aqueous vapour
`tension. As 83 per cent. phosphoric acid and 62 per cent. sulphuric
`
`* Z. physikal. Chem., 1939, B, 45, 156--164.
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 017
`
`

`

`THE CONSTITUTION OF COLOURED GLASSES.
`
`.11
`
`400
`
`Absorption of Iodine in Hexane.
`Benzene Mixture.
`A maximum.
`Solvent.
`Hexane, pure
`525 m~.
`,, -l- 14-3% benzene 515 ,,
`,,
`,,
`507
`,, + 28-6°,/o
`,,
`505
`,,
`-~ 54"5%
`Benzene, pure
`500
`,,
`
`Curve.
`1
`2
`3
`4
`5
`
`40O
`
`500
`Fie. 2.
`
`600 m~.
`
`Absorption of Iodine in Hexane.
`Toluene Mixture.
`
`Curve.
`1
`2
`3
`4
`5
`
`Solren|.
`A maximnm.
`Hexane, pure
`525 m~.
`,,
`,,
`+ 14"3% toluene 515
`,, ÷ 28"6"/o
`,,
`510
`,,
`,,
`,,
`505
`,,
`+ 54.5%
`Toluene, pure
`486
`
`0’5
`
`0-25,
`
`zi/}
`/1
`///
`
`0.25 //////
`
`400
`
`500
`Fro. 3.
`
`600
`
`400
`
`500
`Fro. 4,
`
`600 m~.
`
`Absorption of Iodine in Hexane-
`Ether Mixture.
`
`Absorption of Iodine in Hexane.
`Ethyl Alcohol M4vture.
`
`Curve,
`1
`2
`3
`4
`5
`6
`7
`
`Solvent.
`!~exane, pure
`2.28°/o ether
`,,
`4-56~
`,,
`7"15%
`.
`8-60%
`.
`28"60%
`Eth~x~ pure
`
`A maxiTnum.
`525 mg.
`520
`,,
`,,
`510
`500 .
`493 .
`465 .
`450 .
`
`Curre.
`1
`2
`3
`4
`5
`6
`7
`8
`
`Solvent.
`ttexane, pure
`0.57q~ alcohol
`,,
`2-28%
`,,
`2.86%
`,,
`5"70%
`,,
`8.55%
`,,
`11.25%
`,,
`28,60%
`
`A maximum.
`525 m~.
`520
`,,
`505
`,,
`502
`,,
`462
`,,
`450
`,,
`,,
`446
`443
`,,
`
`O-I Glass, Inc.
`Exhibit 1042
`Page 018
`
`

`

`COLOURED OLASSES.
`
`acid solutions have the same vapour tension and, therefore, the
`same dehydrating effect, they shift the absorption band of a dye by
`the same amount.
`
`TEE II~FLUENCE OF ADSORPTION.
`if a chromophore is adsorbed at the surface of a crystal, it is
`subjected to the electric fields originating from the crystal surface.
`This