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We describe a case of left cervical stage I centroblastic lymphoma in a 29-year old male patient with Down's syndrome due to a (14; 21) Robertsonian translocation. The disease presented as extensive lymph node necrosis leaving rare areas of tumor cells, accounting for the diagnostic difficulties. According to our review ofthe literature, lymphoma is one of the most common neoplasms in DS patients and may represent the second most common malignancy in this condition, far behind leukemia.

Some aspects of the reactivity of disphosphene RP=PR 1 (R = (Me3Si)3C) are described, particularly reduction (LiAlH4), electrophilic additions (HCl, Cl2), heterocyclisation reactions (S8).The very bulky (Me3 Si)3C group well stabilizes the adducts RP(H)P(H)R 5, RP(H)P(Cl)R 6, RP(H)Cl 7, RP(Cl)P(Cl)R 8, [image omitted] 11 such compounds being often unstable.Structure of 1 was determined by single crystal X-ray diffraction. 1 crystallizes in the triclinic space group; two independent centro-symmetric molecules are present in the unit cell, one of them shows a disorder at the level of silicon atoms; the P=P bond lengths are respectively 2.003(3) and 2.001(3) Å. Data are listed in Tables I to IV. All other crystallographic data are deposited with the Cambridge Crystallographic Data Centre (CCDC).Quelques aspects de la réactivité du diphosphène RP=PR 1 (R = (Me3Si)3C) sont présentés, en particulier des réactions de réduction (LiAlH4), d'additions électrophiles (HCl, Cl2) et d'hétérocyclisation (S8).Dans les adduits obtenus, RP(H)P(H)R 5, RP(H)P(Cl)R 6, RP(H)Cl 7, RP(Cl)P(Cl)R 8, [image omitted] 11, le substituant (Me3Si)3C, très encombrant, stabilise remarquablement des structures habituellement peu stables.La structure cristalline de 1 a été déterminée par diffraction de RX. 1 cristallise dans le système triclinique; deux molécules centrosyétriques indeépendantes sont présentes dans la maille, l'une d'elles montre un désordre au niveau des atomes de silicium; les longueurs de liaison P=P sont respectivement 2.003(3) et 2.001(3)A.

Within a general study of new precursors of germa-imines, a series of N-monohalogermyl secondary amines of the type R2Ge(X)NHR' (R= Me, Et, Ph; R'= Mes, tBu3C6H2; X= Cl, F) stabilized by steric hindrance was synthesized. These compounds were obtained through aminolysis of germanium-halogen bonds by primary amines or by lithium derivatives of these primary amines. The halogermylamines thus formed are thermally unstable and decompose by symmetrisation leading principally to the corresponding dihalogermanes. Methanoly-sis of the Ge-N bond leads to the corresponding halomethoxygermanium compounds.Abstraction of hydrogen halide leads to the expected transient germa-imine or to the corresponding dimer: the sterically hindered cyclodigermazane not obtainable by other methods.Cleavage reactions of sterically hindered cyclodigermazanes by Et3N, HCl does not lead to halogermyl secondary amines but to bis-(diorganohalogermyl) tertiary amines.

New organophosphorus compounds utilized as haptens in immunology against organophosphorus compounds, inhibitors of acetylcholinesterase, have been synthesized. These compounds have structures similar to that of the organophosphorus nerve agent VX : [O-ethyl S-(2-(diisopropylamino)ethyl)methylphosphonothioate] [image omitted] by substitution of the S-atom by an O-atom or CH2 group, and by introduction of aryl, alkyl or alkylaryl groups instead of an ethyl group.

New (8-methoxy-1-naphthyl)arylgermanes 1a−c are synthesized. The crystal structure of 1b (aryl = mesityl), determined by X-ray diffraction, shows that an intramolecular interaction occurs between the oxygen and germanium atoms, the Ge- - -O distance being 2.75 Å. The corresponding (diarylgermyl)lithiums R2HGeLi are prepared in high yield by hydrogermolysis of tert-butyllithium in THF and are susprisingly stable. Their characterization by ¹H, ¹³C, and ⁷Li NMR spectroscopy is reported. Dimetalation of the initial arylgermanes depends upon steric hindrance around the germanium atom and the nature of the organolithium compound RLi. The reaction of 1a or 1c with n-BuLi followed by MeI affords the expected dialkylation product, whereas 1b gives the unexpected iodide 5b due to steric hindrance around the germanium atom.

New stable compounds with a germanium (or a tin)-phosphorus double bond have been prepared respectively by a one step reaction between a lithiophosphide and a difluorogermane, or by dehydrofluorination of the corresponding fluorostannyl-phosphine with tert-butyllithium. Various types of cycloadditions ([2+2], [2+3] and [2+4]) have been observed with aldehydes, nitrones and α-ethylenic aldehydes and ketones.

The reaction of tert-butyllithium with (fluorodimesitylgermyl)- and (chlorodimesitylgermyl)phenylacetonitrile (4a,b) leads to the lithium salts 5a (X = F) and 5b (X = Cl), which exhibit an ambident character:  [>C^-−C&tbd1;N↔>C&dbd;C&dbd;N^-]Li⁺. Quenching of 5a with triphenylbromomethane affords the germylketenimine 8, Mes2FGeC(Ph)&dbd;C&dbd;NCPh3. ¹H dynamic NMR spectroscopy allows the determination of the activation energy of the nitrogen inversion ΔG* = 9.9 ± 0.2 kcal/mol. In the absence of a trapping reagent, 5 undergoes an elimination of lithium halide with formation of the eight-membered cyclic C,N-bis(germadiyl) bis(ketenimine) 1, which is the first ring containing two ketenimine moieties. 1 has been characterized by IR (ν(C&dbd;C&dbd;N) 2015 cm^-1) and ¹³C NMR spectroscopy (170.87 ppm for the sp carbon) and by an X-ray structure determination, which displays a “cyclohexane” type structure in a chair conformation.

Thermal treatment of Nb(η⁵-C5H4SiMe3)2(H)3 (1) with the appropriate organogermanium hydrides (HGeR3) and HSnPh3 gives the corresponding niobocene germyl hydrides Nb(η⁵-C5H4SiMe3)2(H)2(GeR3), GeR3&dbd;GePh3 (2), GePh2H (3), GeEt3 (4), Ge(C6H13)3 (5), GeⁱAm3 (ⁱAm = CH2CH2CH(CH3)2) (6), Ge(C6H13)2Cl (7), GeⁱAm2Cl (8), Ge(C6H13)2H (9), GeⁱAm2H (10), and Nb(η⁵-C5H4SiMe3)2(H)2(SnPh3) (11) in good yields. Spectroscopic data indicate the presence of only one of the two possible structural isomers in which the germyl or stannyl group is in the equatorial plane with a symmetrical structure. Reactivity studies on the series Nb(η⁵-C5H4SiMe3)2(H)2(ER3), E = Si (12), Ge (2), Sn (11), were carried out. 12 reacts with H2 to give 1, but 2 and 11 were unreactive toward this reagent. Furthermore, a similar behavior was observed with CO and CN(2,6-Me2C6H3). Thus, 12 reacts with these reagents to give rise, after elimination of HSiPh3, to Nb(η⁵-C5H4SiMe3)2(H)(CO) and Nb(η⁵-C5H4SiMe3)2(H)(CN(2,6-Me2C6H3)), respectively, while 2 and 11 do not react. Reactions of 12 with HGePh3 and HSnPh3 and of 2 with HSnPh3 gave σ-bond metathesis products, but no reactions were observed between 2 and HSiPh3 or between 11 and HSiPh3 or 11 and HGePh3. The kinetics of these processes have been studied by ¹H NMR spectroscopy and indicated the following reactivity trends Nb−SiPh3 > Nb−GePh3 > Nb−SnPh3 for the different processes considered. The X-ray molecular structures of 2 and 11 were established by diffraction studies. The two isostructural complexes show a bent-sandwich coordination with the two hydrides flanking either side of the Nb−Ge and Nb−Sn bonds (2.710(1), 2.830(1) Å in 2 and 11, respectively).

New cyclic oligomers of dimesitylgermylene carbodiimides (Mes2GeNCN)n (n = 3 (1) and 4 (2)) were synthesized by reactions of dimesityldichlorogermane with either cyanamide in the presence of triethylamine or lithium cyanamide. The reactions always gave 1, the trimer of the hypothetical (Mes2Ge&dbd;N−CN), as the major compound. Higher oligomers 3 (n up to 20−30) also can be isolated, depending on the reaction conditions. In THF solution at room temperature, 2 and 3 slowly isomerize to 1, which seems to be the most stable compound. X-ray analysis of trimer 1 and tetramer 2 shows unstrained tetrahedral germanium atoms and linear diimine linkers.

Various aspects of the reactivity of the first stable germaphosphene 1 and stannaphosphene 6 are described.

Germyl derivatives of N-2,4,6-trifluoroaniline were synthesized either by dehydrohalogenation between halogermanes and 2,4,6-trifluoroaniline over DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) or by elimination between halogermanes and 2,4,6-trifluoroanilinolithium. Dimesitylfluorogermyl N-2,4,6-trifluoroanilino-lithium stabilized by THF slowly eliminated lithium fluoride leading to 2,4(2,4,6-trifluorophenyl)-1,3-tetramesitylcyclodigermazane, mainly through intermolecular elimination while in the presence of MgBr2 or tBuMgBr the corresponding germa-imine was formed. Dimesitylchlorogermyl-2,4,6-trifluoroanilino lithium also led to cyclodigermazane while the corresponding bromogermyl lithium or magnesium compound gave mainly the stable 2,4,6-trifluorophenyl dimesitylgerma-imine by intramolecular elimination. The same stable germa-imine was also obtained by exchange reaction between dichlorodimesitylgermane and N-bis(triethylgermyl)2,4,6-trifluoroaniline. Reactivities of monomeric germa-imine and its dimer cyclodigermazane are compared. The dimer is almost inert towards water and methanol and does not react with chloroform and N-tert-butylphenyl nitrone while the germa-imine leads to the corresponding adducts. The adduct with chloroform through α-elimination of dichlorocarbene gave N-dimesitylchlorogermyl trifluoroaniline. The electron withrawing effects of the trifluorophenyl group on nitrogen stabilize the germa-imine, preventing its dimerization, but also induce a decrease in reactivity of germanium nitrogen compounds within the series.

Dichlorogermylporphyrins have been obtained from the reaction of GeCl4 or GeCl2. dioxane with porphyrin TMPyPH2, TAPPH2 and TPPSH2 in quinoline or pyridine. These dichlorogermyl porphyrins reacted in pyridine with HSCH2CH2NH.X (X=H.HCl, -(CH2)3NH2.2HCl) to lead to germylporphyrins with new ligands on germanium : cysteamine and N-(2-thioethyl)-1,3-diami nopropane hydrochloride.

Sterically hindered trimesitylgermylamine is a rare example of a stable primary germylamine. X-ray structural data show that germanium is shielded from nucleophilic attack by the surrounding mesityl groups. Nitrogen is still accessible, and the only reactions which occur are those in which the first step of the transition state proceeds through an electrophilic attack on nitrogen.With acid chlorides, Mes3GeNH2 reacts mainly as a primary amine forming the corresponding N-germylamides. The primary amine behaviour is also evident in the reaction with aldehydes. However, functional hydrogen cannot be substituted by lithium, probably because of steric hindrance which prevents the approach of an organolithium derivative.Insertion reactions into the Ge-N bond are difficult. Carbon dioxide and disulfide react only upon heating and yield trimesitylgermyliso- or isothiocyanates (Mes3GeN=C=X; X=O, S) through thermal degradation of the carbamate or dithiocarbamate initially formed. 3,5-di-tert-butylorthoquinone does not form an adduct with Mes3GeNH2, but is slowly transformed into 3,5-di-tert-butylorthocatechol.In spite of its steric hindrance, the trimesitylgermylamino group failed to stabilize a N-germylated germa-imine since the precursor Mes3Ge(Cl)NH-GeMes3 is not stable and gave cyclodigermazane (Mes3GeNH)2 and trimesitylgermyl chloride through Ge-Cl/Ge-N exchange reactions.La trimesitylgermylamine steriquement encombree, est un des rares exemples d'amines primaires du germanium qui soit stable thermiquement. Sa structure determinee par diffractometrie de rayons X montre que le germanium est completement protege des attaques nucleophiles par les groupements mesityles qui l'entourent. Seul l'azote reste relativement accessible et les reactions obtenues sont celles ou la premiere etape de l'etat de transition se fait par une attaque electrophile de l'azote.Avec les chlorures d'acide, la trimesitylgermylamine se comporte plutot comme une amine primaire et conduit de facon preponderante a l'amide N-germanie correspondant. Ce comportement d'amine primaire a pu etre mis en evidence egalement avec les aldehydes. Cependant, il N'a pas ete possible de substituer l'hydrogene fonctionnel par le lithium, vraisemblablement en raison des difficultes d'approche de l'organolithien.Les reactions d'insertion dans la liaison Ge-N sont difficiles. Avec le dioxyde et le disulfure de carbone, elles ne se font qu'a chaud et seuls sont obtenus les trimesitylgermyl iso- ou isothio-cyanates (Mes3GeN=C=X; X=O, S) provenant de la degradation thermique des carbamates ou dithiocarbamates prealablement formes. Les reactions de clivage avec l'eau, les alcools, les hydracides sont egalement lentes et difficiles. La 3,5-di-tert-butylorthoquinone ne donne pas d'adduit avec Mes3GeNH2 mais est lentement transformee en 3,5-di-tert-butylortho catechol.Malgre l'encombrement sterique, le groupement trimesitylgermylamino N'a pas pemis d'obtenir une germa-imine stable car le precurseur Mes2Ge(Cl)NH-GeMes3 est lui-meme instable et conduit par echange des liaisons Ge-Cl/Ge-N au cyclodigermazane (Mes2GeNH)2 avec formation de chlorure de trimesitylgermanium.

De nouveaux phosphonates (1-6) et dithiaphosphonates (11) germaniés cycliques des types oxo-2dioxa-et thio-2 dithiaphosphagermetannes-1,3,2,4 sont obtenus à partir de dichlorures organogermaniés soit par réaction de déchlorhydratation avec l'acide phénylphosphonique, soit par action de l'anisyltrithiophosphonate d'ammonium. On observe une dimérisation des dioxaphosphagermetannes MeRGeOP(O)(Ph)O [R=Me (1) ou Ph (2)], et une décomDosition de Mes2GeOP(O)(Me)O (5) conduisant à (Mes2GeO)2. (MePO2)2, et Mes2GeOGe(Mes2)OP(O)(Me)O (6) via ies espèces instables [Mes2Ge=O] et (MePo2), Par contre Mes2GeSP(S)(An)S (11) est stable à température ambiante à l'état solide, et peut etre isolé pur. Cet hétérocycle se décompose à 250°C pour donner les espèces transitoires [Mes2Ge=S] et [AnPS2].

Diffèrents modes de synthèse d'oxazolidones 1.2.4-7 et de dioxolonnes 8-11 germaniées sont décrites.La stabilité thermique de germadioxolonnes a été étudiée. La décomposition procède d'un méchanisme du type (2 + 2 + 1), avec ouverture du cycle et formation de germylène.La réactivité chimique des oxazolidones et dioxolonnes germaniées a été étudité. Des réactions d'échange avec des dérives organominéraux dichlorés conduit facilement et avec de bons rendements aux derives isologues, phosphorés(III). arseniés(III), soufrés. ou germaniés(IV). La réaction d'échange entre une dioxolonne germaniée et le dichlorogermylène nous a permis d'obtenir un nouveau germylène fonctionnel cyclique stable 20 qui a été caractérisé par spectrographie (RMN 1H. masse).Different synthetic ways for germaoxazolidones 1.2.4-7 or dioxolonnes 8-11 have been described.The thermal stability of germadioxolonnes has been studied. Decomposition occurs by a [2 + 2 + 1] ring opening with formation of germylene.The chemical reactivity of germaoxazolidones or dioxolonnes has been studied. Exchange reactions with dihalogenated covalent compounds occur readily lcading to phosphorus(III). arsenic(III). sulphur or germanium(IV) analogs.From dichlorogermylene, new stable fonctionnal cyclic germylene 20 is obtained and characterized.

Synthesis of cyclic germanium derivatives of salicylic and thiosalicylic acid are described by two different ways. These derivatives are characterized by NMR and mass spectrometry. Their thermal decomposition is studied.Exchange reactions between these derivatives and GeCl4 and GeCl2 lead to spirogermanium compounds and new stable germylenes characterized by cycloaddition with dimethyl butadiene and di-t-butyl o-quinone.Cyclic germanium derivatives of α-hydroxyacids also lead to spirogermanium compound and cyclic germylene by reaction respectively with GeCl4 and GeCl2.

Transient metallaphosphenes (rbnd2;M=P-) have been obtained by exchange reactions between disilylphosphines and organometaldihalides (M = Ge, Sn), or by thermolysis of 2-metallaphosphetanes (M = Si, Ge). They are characterized by trapping reactions with strained heterocycles. The first stable germaphosphene 12 has been synthesized by dehydrohalogenation from the parent halogermylphosphine and isolated in form of orange crystals. It is very reactive toward compounds with active hydrogen.Transient diphosphenes (-P=P-) have been prepared by the same type of exchange reactions between disilylphosphines and dichlorophosphines and characterized by trapping reactions on dienes. The second stable diphosphene 18 has been obtained by addition of t-BuLi on trisyldichlorophosphine. Its structure has been determined by X-ray diffraction and some aspects of its reactivity are described. The reaction of bisyltrichlorogermylphosphine with DBU affords the new stable and potentially reactive diphosphene 30.

Two new diphosphenes 7 and 10 have been synthesized by action of DBU on trichlorogermylphosphines 4 and 8; this route involves the intermediate formation of chlorophosphines 5 and 9. Diphosphenes 7 and 10 are stabilized by the 2,6-bis(trifuoromethyl)phenyl group which presents both steric and electronic effects and is used for the first time in phosphorus chemistry.

New 8-(methoxynaphthyl)hydridogermanium triflates and iodides were synthesized by treatment of the corresponding germanes with trifluoromethanesulfonic acid or I2. Their characterization by ¹H and ¹³C NMR and IR spectroscopy is reported. In the solid state, bis(8-methoxynaphthyl)hydridogermanium triflate (6) exhibits a 5-coordinate germanium atom weakly linked to the triflate anion. The germyl iodide rapidly gives the germoxolene with loss of MeI when it is heated in CH3CN. With H2O, amine, and DMSO, the germyl triflates react quantitatively to form new complexes which can be isolated and characterized. The X-ray crystal structure of the hydrate of bis(8-methoxynaphthyl)hydridogermanium triflate (11) shows the predominant formation of a hydrated germyl cation. Several tentative approaches to prepare germanols failed and always gave stable germoxanes instead.

Les hétédrocycles à six chainons Me2GeCH2Ge(Me2SP(S)(An)S (1) et Me2GeCH2SP(S)(An)SCH2 (2) ont été obtenus par action de l'anisyltrithiophosphonate d'ammonium sur les dihalogénures organogermaniés correspondants (Me2C1Ge)2CH2 et Me2Ge(CH2I)2 La thermolyse de 1 conduit, via les espèces intermédiaires thiadigemétane [Me2GeCH2Ge(Me2)S], germaéthene [Me2Ge=CH2 et germathione [Mg2Ge=S aux hétérocycles germaniés Me2GeCH2Ge(Me)SGe(Ms)CH2Ge(Me2)S (3) Me2GeCH2Ge(Me2SGe(Me2 (4) et Me2GeSGe(Me2)CH2Ge(Me2)CH2 (5). Les réactions d'échange entrel et divers chlorures sont décrites. Avec les chlorures du type P,MCl2 les réactions conduisent aux espèces intermédiaires [AnPS2] et [ΣM=S]; avec SC12 la réaction permet d'accéder au soufre singulet ['S2].

The use of exchange reactions Ge-X/Ge-Y (X = halogen; Y = MeO, MeS) between phenylhalogermanes or polygermanes and functional trialkylgermanes may give selectively and quantitatively various substituted phenylgermanes and polygermanes.These reactions are readily adapted to the synthesis of X2(Y)GeH, Ph(X)(Y)GeH, PhY2GeGeY2Ph, (PhY2Ge)2Ge(Y)Ph, (PhY2Ge)3GePh derivatives which may not be obtained by direct action of organometallic compounds YM (M = Li, Na, MgX) in basic solvents.Germanium-hydrogen bonds also give similar exchange reactions of the Ge-H/Ge-Y type; but these latter reactions probably are of the radical type and always lead to equilibria.

A case of Pacinian hyperplasia of the right great toe is reported. Pacinian hyperplasia is a rare benign and recently recognized painful lesion composed of an excess of well formed or hyperplastic Pacinian corpuscules, normaly involved in sensory innervation. This lesion that is usually observed in the hand, must be distinguished from nerve tumors harboring onion-bulb structure which are not true well formed Pacinian corpuscules and from Morton neuroma. Pacinian hyperplasia is considered a reactive lesion and not a true neoplasm. To our knowledge, this case is the first described in the foot.

The first arsaphosphaallene, ArP&dbd;C&dbd;AsAr (1; Ar = 2,4,6-tri-tert-butylphenyl), has been synthesized by debromofluorination of the (phosphaalkenyl)fluoroarsane 5 by n-butyllithium at low temperature and characterized by NMR (δP +159.7 ppm, δC +299.5 ppm) and X-ray analysis. A ¹H NMR study between +55 and −60 °C allowed the determination of the rotation barrier of Ar groups.

Addition of tert-butyllithium to chloroborylphosphine 2to give 3and 4provides evidence for the phosphaborene 1, a compound with dicoordinated double-bonded boron and phosphorus.

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