Tetrylidynes [(Me3P)2(Ph3P)Rh≡SnAr*] (10) and [(Me3P)2(Ph3P)Rh≡PbAr*] (11) are accessed for the first time via dehydrogenation of dihydrides [(Ph3P)2RhH2SnAr*] (3) and [(Ph3P)2RhH2PbAr*] (7) (Ar*=2,6‐Trip2C6H3, Trip=2,4,6‐triisopropylphenyl), respectively. Tin dihydride 3 was either synthesized in reaction of the dihydridostannate [Ar*SnH2]− with [(Ph3P)3RhCl] or via reaction between hydrides [(Ph3P)3RhH] and 1/2  [(Ar*SnH)2]. Homologous lead hydride [(Ph3P)2RhH2PbAr*] (7) was synthesized analogously from [(Ph3P)3RhH] and 1/2  [(Ar*PbH)2]. Abstraction of hydrogen from 3 and 7 supported by styrene and trimethylphosphine addition yields tetrylidynes 10 and 11. Stannylidyne 10 was also characterized by 119Sn Mössbauer spectroscopy. Hydrogenation of the triple bonds at room temperature with excess H2 gives the cis‐dihydride [(Me3P)2(Ph3P)RhH2PbAr*] (12) and the tetrahydride [(Me3P)2(Ph3P)RhH2SnH2Ar*] (14). Complex 14 eliminates spontaneously one equivalent of hydrogen at room temperature to give the dihydride [(Me3P)2(Ph3P)RhH2SnAr*] (13). Hydrogen addition and elimination at stannylene tin between complexes 13 and 14 is a reversible reaction at room temperature.

Terphenyltin and terphenylgermanium trihydrides were deprotonated in reaction with strong bases, such as LiMe, LDA, or KBn. In the solid state, the Li salts of the germate anion 4 and 4a exhibit a Li–Ge contact. In the Li salt of the dihydridostannate anion 6a, the Li cation is not coordinated at the tin atom instead an interaction of the Li cation with the hydride substituents was found. Evidenced by 1H–7Li-HOESY NMR spectroscopy the Li-salt of the deprotonated tin hydride 6a exhibits in toluene solution a contact between Li cation and hydride substituents, whereas in the 1H–7Li-HOESY NMR spectrum of the homologous germate salt 4a, no crosspeak between hydride and Li signals was found. The organodihydridogermate and -stannate react as nucleophiles with low-valent Group 14 electrophiles. Thus, three compounds were synthesized: Ar–Ë′–EH2–Ar (E′, E = Sn, Ge; Pb, Ge; Pb, Sn; Ar = Ar′, Ar*). Following an alternative synthesis Ar′SnH2PbAr* was synthesized in reaction between [(Ar*PbH)2] and [(Ar′SnH)4] generated in situ. In reaction between low-valent organotin hydride [(Ar*SnH)2] and organdihydridostannate [Ar*SnH2]− formation of distannate [Ar*2Sn2H3]− was found.

Organodihydridoelement anions of germanium and tin were reacted with metallocene dichlorides of Group 4 metals Ti, Zr and Hf. The germate anion [Ar*GeH2]− reacts with hafnocene dichloride under formation of the substitution product [Cp2Hf(GeH2Ar*)2]. Reaction of the organodihydridostannate with metallocene dichlorides affords the reduction products [Cp2M(SnHAr*)2] (M=Ti, Zr, Hf). Abstraction of a hydride substituent from the titanium bis(hydridoorganostannylene) complex results in formation of cation [Cp2M(SnAr*)(SnHAr*)]+ exhibiting a short Ti–Sn interaction. (Ar*=2,6‐Trip2C6H3, Trip=2,4,6‐triisopropylphenyl).

In reaction of tantalocene trihydride with the low valent aryl tin cation [Ar*Sn(C6H6)][Al(OC{CF3}3)4] (1a) the hydridostannylene complex [Cp2TaH2-Sn(H)Ar*][Al(OC{CF3}3)4] (2) was synthesized. Hydride bridged adducts [Cp2WH2EAr*][Al(OC{CF3}3)4] (E = Sn 3a,...

Oligomerization reactions of aliphatic diisocyanates, exclusively involving NCO groups are discussed. The reactivity and selectivity of these reactions are dependent on chain length, reaction conditions, and the catalyst employed. The resulting oligomers (“dimers” and “trimers”) sometimes deviate considerably from expectation with respect to the structure and properties. The synthesis and characterization of well-known derivatives such as uretdiones and isocyanurates are discussed, and special attention is devoted to the recently developed iminooxadiazinedione chemistry. Finally, a new class of compounds is introduced, the tricyclic diiminooxadiazinones.