3,734,963 United States Patent Office Patented May 22, 1973 1. 2 Salts were mixed with a hydrocarbon containing the com 3,734,963 plexing agent, the inorganic lithium salts dissolved in the INORGANIC LITHUM-AMINE COMPLEXES Arthur W. Langer, Jr., Watchung, and Thomas A. Whit reaction medium and stable complexes of the chelating ney, Linden, N.J., assignors to Esso Research and Engi agent with the lithium salt could be obtained from the neering Company reaction mixture. No Drawing. Filed Mar. 18, 1969, Ser. No. 808,328 It is well known that one of the significant factors used Int, C. C07c87/14, 87/20, 87/38 in predicting whether a reaction can be accomplished with U.S. C. 260-563 R 1. Claims a given material is whether the lattice energy of such ma terial is low enough to be overcome by the other reactant 10 So as to form a new compound. Thus, it was highly surpris ABSTRACT OF THE DISCLOSURE ing to find that the inorganic lithium salts which have Complexed inorganic lithium salts are prepared by mix significantly higher lattice energies than those of organo ing an inorganic lithium salt such as a lithium halide with lithium compounds, nevertheless can form complexes with a monomeric or polymeric organic complexing agent which the same type (and indeed many more types) of complex contains at least one nitrogen atom and at least one other 5 ing agent as those used in conjunction with the organo atom which is nitrogen, oxygen, phosphorus or sulfur. lithium compounds. The complexing agent may be nonchelating (e.g. triethyl Finally, it was unexpected to find that inorganic salts enediamine) or chelating in nature. The chelating complex of alkali metals other than lithium (i.e. sodium, potas ing agents (e.g. triamines such as pentamethyl diethylene sium, cesium and rubidium) did not form stable complexes triamine) are preferred. The resultant complex is useful 20 With the same complexing agents, although the general for a variety of processes such as separations, catalytic chemistry of such inorganic alkali metal salts is very reactions, substitution reactions, electrochemical reactions, similar to that of the inorganic lithium metal salts. etc. and as oil and fuel additives. The inorganic lithium salt THE PRIOR ART 25 The first component of the novel complexed inorganic It is well known (e.g. see British Pat. 1,051,269) that lithium salts of this invention is an inorganic lithium salt organolithiums such as n-butyllithium will form chelate having a lattice energy no greater than about that of complexes with certain bifunctional Lewis bases, particu lithium hydride, preferably no greater than about 210 larly di-tertiary amines such as tetramethylethanediamine. 30 kilocalories per mole (measured at about 18 C.). The According to this patent, the compelxes are prepared by lattice energies of various inorganic lithium salts may be mixing the organolithium and the di-tertiary diamine, gen found in the "Handbook of Electrochemical Constants” by erally in the presence of a hydrocarbon solvent or excess Roger Parsons (Academic Press, 1959). amounts of the diamine. The chelate complex forms quite The lithium salts useful for this invention must have rapidly since the organolithium and the diamine form a 35 less than the requisite maximum lattice energy and must homogeneous solution (in a hydrocarbon or excess di also be inorganic in nature; they will normally have melt amine) and the chelate complex may then be isolated by ing points less than about 650° C. The term "inorganic,” removal of the diluent. for the purposes of this invention, means that (1) there is It is also well known (e.g. see British Pat. 1,031,179) no hydrocarbon radical bonded directly to the lithium that alkali metals such as sodium or lithium in finely 40 atom and (2) any hydrocarbon radical present in the anion divided form can be reacted with certain organic com moiety must be indirectly bonded to the lithium through a pounds to produce the corresponding organo alkali metal third atom which cannot be nitrogen, oxygen, phosphorus salts, providing the reaction is carried out in the presence or sulfur. Thus, lithium compounds such as n-butyllithium of certain amines in which at least one of the amino groups and phenylithium do not meet criteria (1) and are out is a primary or secondary amine group. Thus, a lithium 45 side the scope of this invention. Similarly, compounds of dispersion (in heptane) can upon admixture with ethylene the type LiOR, LiNHR or LiNR, LiSR, LiPR, LiOOCR diamine, yield N-lithioethylenediamine; this latter matter do not meet criteria (2) and are therefore outside the scope upon treatment with acetylene will yield monolithium of this invention. On the other hand, compounds of the acetylide ethylenediamine. type LiNH2, LiCN, LiSCN, LiSH, Li2CO3, LiHCO3, 50 LiAlraCl2, LiAlH(OR), LiBH(OR), LiAlkH, etc. are It is also well known (U.S. Pat. 2,726,138) that lithium within the scope of this invention. chloride may be extracted from crude aqueous lithium Specific nonlimiting examples of useful inorganic lithium chloride with the aid of an inert solvent of 3 to 8 carbon salts are those in which the anion is: amide, azide, bi atoms containing at least one nitrogen or oxygen atom such carbonate, chlorate, cyanide, fluosulfonate, chloride, bro as the alkanols, corresponding ketones and aldehydes, 55 mide or iodide, hydrogen sulfate, hydrosulfide, iodate, pyridine and quinoline. nitrate, hypochlorite, nitrite, sulfate, thiocyanate, perchlo THE PRESENT INVENTION rate, Br, I, ClBr2, IBr2, ICl4, BrF, IFs, etc. Also useful are those inorganic lithium salts in which It has now been unexpectedly discovered that a complex the anion is a complex metal anion which may be rep of certain inorganic lithium salts and certain complexing 60 resented by the formula R'MX wherein n is an integer agents can be readily prepared. This is highly surprising of 0 to 6 inclusive depending on the valence of M, n is for the various reasons set forth immediately below. an integer and (n-i-m-1) equals the valence of M, X At the outset, it was surprising that a complex of an is a halogen, R' is a C1-C20 alkyl, aryl or aralkyl radical inorganic lithium salt could be prepared since the general and M is a metal selected from the group consisting of chemistry (i.e. properties, reactivity, etc.) of inorganic 65 beryllium; magnesium; Group 1b elements; Group 2b lithium salts differ drastically from that of organolithium elements; Group 3 elements, Group 4a elements other than compounds or lithium metal. Many organolithium com carbon and silicon; Group 5a elements other than nitrogen; pounds are generally soluble in hydrocarbons and thus and the transition metals, i.e. subgroup b of Groups 4 readily form complexes upon admixture with certain through 8. The Periodic Table employed in describing complexing agents. However, inorganic lithium salts are 70 this invention is that which appears on the back cover of generally insoluble in hydrocarbons; thus, it was wholly “Handbook of Chemistry and Physics” (Chemical Rub unexpected to find that when many inorganic lithium ber Co., 49th edition). 3,734,963 3 4 Nonlimited examples of useful complex metal anions include the hydridoaluminates, the hydridoborates, the (III) (9)a chloroaluminates (tetra-, hepta-, etc.), the aluminum alkyl (II)-Y-(R). halides, AuBr, BF, BeCl4, SnCls, PFs, TiCl, FeCl4, Cr(CO)4, MnCls, Ni(CN), VFs, HgCl3, B2H, UFA, AsF6, etc. (p)a is (p)a Preferably, the inorganic lithium salt is one of the (II)-Y -Y-(II) following: lithium chloride, lithium bromide, lithium (h). (R) a iodide, lithium aluminum hydride, lithium borohydride, (IV) (R) (O)d lithium, nitrate, lithium hexafluorophosphate, lithium tetra O N / fluoroborate, lithium tetraphenylborate, LiAl(CH5)H, (Od -Y (O)d LiAl(C2H5)2H2, LiAl(C2H5)H, LiAl(C2H5)4, lithium X / perchlorate, lithium azide, LiAsF6 and LiBeF. Y Y The complexing agent (R) (R) 5 The complexing agent contains at least two functional wherein a is 1 or 2, depending on the valence of Y or ities: at least one functionality is a secondary amine group, Y', b is 0 or 1, depending on the valence of L or Y'; a tertiary amine group, an amine oxide group, a secondary c is an integer of 0 to 10,000, inclusive; d is 0, 1 or 2, de phosphine group, a thioether group, a sulfone group or a pending on the valence of Y or Y'; e is an integer of 0 sulfoxide group; at least one other functionality is a sec 20 to 3, inclusive; R is the same or different C1-C4 alkyl ondary amine group, a tertiary amine group, an amine ox radical; R' is hydrogen when d is 0 or is the Same or ide group, a secondary phosphine group, a tertiary phos different C1-C4 alkyl radical or C6-C10 aryl or aralkyl phine group, a phosphine oxide group, a thioether group, radical when d is 0, 1 or 2; Y is a nitrogen, sulfur or a Sulfone group, a sulfoxide group or an ether group. phosphorus atom; Y is a nitrogen, oxygen, Sulfur or The terms "amine oxide group” and "phosphine oxide 25 phosphorus atom; and Z is a nonreactive radical Selected group,” for the purposes of this invention mean that the from the group consisting of (1) Ca-Cio cycloaliphatic or underlying amine and phosphine must be tertiary (rather aromatic radicals and their lower alkyl derivatives where than primary or secondary) in nature. Thus, the desired in said radicals are attached to the Y and Y atoms in "amine oxide group' and "phosphine oxide group” have Formula I and the nitrogen atoms in Formula II at 1,2- the formulas: 30 positions on the aromatic rings or 1,2- or 1,3-positions on the cycloaliphatic rings; and (2) 1 to 4 methylenic radicals, wherein each methylenic radical contains 0 to 2 () ) monovalent hydrocarbon radicals of 1 to 6 carbon atoms.