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Here we report the synthesis of aminoborane HN(BCy2) (C6H3-2,6-Me2) (1) (Cy = cyclohexyl), that was successfully deprotonated and its lithium salt {LiN(BCy2) (C6H3-2,6-Me2)}2 (2) has been characterised. The borylamide ligand -N(BCy2) (C6H3-2,6-Me2) was used for the preparation of N→Sn coordinated stannylene [2,6-(Me2NCH2)2C6H3]Sn [N(BCy2) (C6H3-2,6-Me2)] (3) and two coordinate tetrylenes {E [N(BCy2) (C6H3-2,6-Me2)]2} (E = Sn (4), Pb (5)). Experimental and theoretical studies suggested σ character of E-N bonds without additional N(p)→E(p) donation as the result of the preference of N(p)→B(p) donation in 4 and 5. DFT studies on 4 and 5 also reveal theirs HOMO to exhibit E lone pair character and theirs LUMO to include p-orbital character located on metal atoms E.

New preparative methods for halogenation of the cage producing the corresponding [2-NH3-B10X9]- species (2- to 4-, X = Cl, Br, I) have been developed using halogenations by elemental halogens in a glass pressure vessel. Compared to similar icosahedral species of formulation [1-H3N-B12X11]- (X = Cl, Br), the N-alkylation reactions in 10-vertex series proceed significantly more easily. The reason for this difference is conceivably due to the two orders of magnitude lower basicity of the amino group, with pKa values in the interval from 9.27 to 8.37, and slightly lower steric strain around the reaction centre. Thus methylations with MeI under mild conditions provided the whole series of corresponding quarternary amines of the formulation [2-Me3N-B10X9]- (5- to 7-, X = Cl, Br, I). The effect of the steric strain of the surrounding halogens on the reactivity at the NH3- centre could then be better seen from reactions with bulkier benzyl bromide. Under comparable conditions, these reactions resulted in the ready formation of disubstituted compounds in case of X = Cl (8-), mixture of mono and disubstituted derivatives for X = Br (9-, 10-) or in monosubstited product for X = I (11-) only. Dibenzyl derivative of the nonaiodinated products (12-) could be still obtained, however only under more forcing conditions. The single-crystal X-ray diffraction structures of all three polyhalogenated derivatives 2- to 4- are presented along with that for benzyl derivative 10-, spectral and physicochemical properties of these polyhalogenated systems are outlined along with specific insights into specific properties of the NH3 group.

A series of tri- and diorganotin(IV) nitrates and nitrites bearing the 2-( N,N -dimethylaminomethyl)phenyl-as a C,N -chelating ligand (L CN ) has been prepared and structurally characterized. Air-stable triorganotin(IV) nitrates and nitrites of the type L CN R 2 SnX (for X = NO 3 : R = n -Bu ( 1 ), R = Ph ( 2 ); for X = NO 2 : R = n -Bu ( 7 ), R = Ph ( 8 )) and (L CN ) 2 ( n -Bu)SnX (X = NO 3 ( 3 ), NO 2 ( 9 )) are monomeric both in solution and solid state with distorted trigonal bipyramidal geometry around the central tin atom. These species were prepared in biphasic systems (water/organic solvent) using AgNO 3 and NaNO 2 , respectively. Diorganotin(IV) dinitrates ( i.e. L CN ( n -Bu)Sn(NO 3 ) 2 ( 4 ), L CN PhSn(NO 3 ) 2 ( 5 ) and (L CN ) 2 Sn(NO 3 ) 2 ( 6 )) and dinitrites ( i.e. L CN ( n -Bu)Sn(NO 2 ) 2 ( 10 ), L CN PhSn(NO 2 ) 2 ( 11 ) and (L CN ) 2 Sn(NO 2 ) 2 ( 12 )) are monomeric species due to the bidentate bonding fashion of the nitrato, nitrito and/or L CN substituents. Compounds 4–6 and 10–12 were prepared under an inert atmosphere using AgNO 3 in acetonitrile and KNO 2 in THF/benzene mixture of solvents, respectively. All these extraordinary stable compounds have been characterized by IR and NMR spectroscopy. In addition, solid-state structures of 2 , 4 , 5 , 6 , 8 , 11 , 12 and one decomposition product of 10 ( i.e. [L CN ( n -Bu)Sn(NO 3 )(μ-OH)] 2 ; 4a ) were determined by the SC-XRD techniques.

The reaction of N,C,N -chelated pnictinidenes ArE(I) [where Ar = C 6 H 3 -2,6-(CH=N t -Bu) 2 , E = As ( 1 ) and Sb ( 2 )] with dimeric complexes [(COD)M(μ-Cl)] 2 (where COD = 1,5-cyclooctadiene, M = Rh or Ir) gave pnictinidene complexes [ArEM(Cl) (COD)] [where E = As, M = Ir ( 3 ) and E = Sb, M = Ir ( 4 ), Rh ( 6 )] that were characterized by the help of 1 H and 13 C NMR spectroscopy and in the case of 3 and 6 also with the single-crystal X-ray diffraction analysis. However, the complex [ArAsRh(Cl) (COD)] ( 5 ) could not be isolated and exists only in an equilibrium with starting compounds in solution. The treatment of other Rh(I) precursors, such as [(COT) 2 Rh (μ-Cl)] 2 (COT = cyclooctene), with 1 or 2 led to the rhodium (III) pincer complex ArRhCl 2 ( 7 ) as a results of a transmetalation. Complex 7 was completely characterized including the single-crystal X-ray diffraction analysis. Finally, the reactivity toward the rhodium(I) carbonyl complex [(CO) 2 Rh (μ-Cl)] 2 was studied. In the case of the stibinidene 1 , an insoluble material was obtained, while the arsinidine derivative cis -[ArAsRh(Cl) (CO) 2 ] ( 8 ) could be isolated and characterized by NMR and IR spectroscopy.

Lithium amidinate complexes were prepared by direct reactions from various nitriles - R1-C N (R = Ph, n-Bu, t-Bu) and trimethylsilyl-substituted lithium amides - R2(Me3Si)NLi (R2 = Ph, 2,6-(CH3)2C6H3 (Dmp) and 2,6-[(CH3)2CH]2C6H3 (Dipp)). All the reactions proceed only in coordinating solvents as diethylether or THF where the migration of the trimethylsilyl group to the nitrogen atom of the parent nitrile is favoured. In the case of t-BuCN, virtually no conversion to appropriate lithium amidinate was observed under the same reaction protocol. Only the adduct of the composition {(t-BuCN){2,6-[(CH3)2CH]2C6H3}(Me3Si)NLi]}2 was isolated from the reaction of t-BuCN with {2,6-[(CH3)2CH]2C6H3}(Me3Si)NLi]} carried out in hexane or toluene solution. Lithium atoms in this adduct appear in trigonal planar to pyramidal coordination neighborhoods. The structure of lithium amidinates in the solid state is strongly dependent on the substitution pattern, when the Dipp substituent is present, complexes always crystallize as mononuclear species with isobidentate bonding fashion of the amidinate and two molecules of solvent being extra-coordinated to the lithium atom. On contrary, smaller peripheral groups do not protect the lithium atom from further association and those complexes are described as di- or trinuclear adducts with less than two coordinated molecules of solvent per lithium atom. In all lithium amidinates prepared, the central lithium atom has distorted tetrahedral coordination geometry with ligands going from anisobidenate or bidentate-bridging to tridentate bonding fashion except the trinuclear complex bearing the smallest combination of ligands where one of the lithium atoms is found in the trigonal planar vicinity.

Sequential methylation of the 8-R-nido-7,8,9-C3B8H11 tricarbollides (R = Ph, p-tol and 2-naphthyl (2-naph)) in the presence of NaH in THF proceeds on the open-face B(10,11) positions to generate mono and dimethyl derivatives, 8-R-nido-7,8,9-C3B8H10-10-Me and 8-R-nido-7,8,9-C3B8H9-10,11-Me2. To demonstrate the general character of the alkylation procedure, B-dialkyl derivatives 8-Ph-nido-7,8,9-C3B8H9-10,11-R12 (R1 = C3H5 (All) and CH2Ph) were prepared via analogous alkylation of 8-Ph-nido-7,8,9-C3B8H11 with allyl and benzyl bromides. The structures were substantiated by multinuclear (11B, 1H and 13C) NMR spectroscopy and that of 8-Ph-nido-7,8,9-C3B8H9-10,11-Me2 was determined by an X-ray diffraction analysis.

Thermal rearrangement of the Na+[8-R-nido-7,8,9-C3B8H10]¯ salts (R = Ph, p-tol, and 2-naph = 2-napthhyl), followed by protonation with conc. H2SO4, proceeds via an unexpected 8 → 7 rearrangement of the cluster RC unit under the formation of the neutral 7-R-nido-7,8,9-C3B8H11 tricarbollides. A C-vertex swing mechanism, involving an unstable 2,7,8-intermediate, was proposed for this rearrangement and substantiated via MP2/6-31G* calculations. Removal of the bridging hydrogen from 7-R-nido-7,8,9-C3B8H11 with Et3N leads to the Et3NH+ salts of the corresponding [7-R-nido-7,8,9-C3B8H10]¯ anions. All the compounds isolated were characterized by multinuclear (11B, 1H, and 13C) NMR spectroscopy and the structures of the simplest 7-Me derivatives were optimized at the MP2/6-31G* level of theory, the structures being verified by GIAO-MP2 computations. The structure of the starting 8-(p-tol)-nido-7,8,9-C3B8H11 was determined by an X-ray diffraction study.

Five coumarin-based polarized ethylenes (enaminoketones, enaminoester and enaminoamide) were prepared using the condensation of the parent β-dicarbonyl compounds with 6-aminocoumarin. Reaction of the polarized ethylenes with an appropriate source of trivalent boron gave corresponding boron β-iminoenolates having either BF2 or BPh2 fragment. The prepared iminoenolates were characterized by means of multinuclear magnetic resonance in solution, single-crystal X-ray diffraction and UV/Vis spectroscopy. A preliminary luminescence study of the iminoenolates as well as their parent enamines was done. The compounds exhibited fluorescence in a solid state as well as in a frozen 2-methyltetrahydrofuran at 77 K. Exploratory tests showed promising AIE/AIEE properties of the tested compounds. On the other hand, no fluorescence in a solution state (with one exception) was observed.

Bifunctional ketiminate zinc complexes were synthesized via alkyl or LiCl elimination route from appropriate zinc species (ZnCl2 or ZnEt2) and methoxyaryl substituted monoanionic ketimine {[2- or 3- or 4-(MeO)C6H4]}N(H)C(Me)=CHC(Me)=O. Homo- or heteroleptic complexes were prepared and characterized by the help of multinuclear NMR spectroscopy techniques. One of the heteroleptic ethyl substituted zinc complexes - {κ2-N,O-[(2-MeO)C6H4N C(Me)–CH C(Me)–O]ZnEt}2 was selected for further reactivity experiments with alcohols and amines. Molecular structures of some products were determined by X-Ray diffraction methods showing di- or trinuclear arrangement in solid state caused by the presence of intramolecular zinc–oxygen or zinc–nitrogen bridges. {κ2-N,O-[(2-MeO)C6H4N C(Me)–CH C(Me)–O]ZnEt}2 was also screened for of its catalytic activity in co/polymerization reactions (ROP: trimethylene carbonate, ɛ-caprolactone, l -lactide; copolymerization of epoxides with CO2).

Reactivity of trimethylaluminium, dimethylaluminium chloride and methylaluminium dichloride with N,N′-diisopropyl-, N,N′-dicyclohexyl- or N,N′-bis(diisopropylphenyl) carbodiimide (Dipp-N C N-Dipp) via the nucleophilic addition mechanism was studied. Six aluminium(III) complexes containing amidinato ligands were prepared and isolated. All reactions as well as the purity and structural confirmation of products were monitored using 1H and 13C NMR techniques. Reactions of prepared [Dipp-N-C(Me)–N-Dipp]AlMeCl with potassium mirror or pivalonitrile were also investigated. Molecular structures of five aluminium(III) mono- or bisamidinates and two dinuclear oxo-aluminium(III) amidinato by-products displaying four- or five-coordinated aluminium atom were determined by X-ray diffraction techniques.

Five aluminium complexes containing N,N'-chelating ligands ([2-(Me2NCH2)C6H4N(R)]−; R = H, SiMe3 or benzyl (Bn)) were prepared and structurally characterized by NMR and crystallographic techniques. Aluminium atoms in all compounds are pseudotetrahedrally coordinated with extremely short intramolecular interaction of the pendant amino group (d(Al–N) = 1.96–2.00 A). The catalytic performance of selected complexes (∼0.1–0.2 mol. %), either with or without an external co-initiator, in ring opening (co)polymerization of e-caprolactone, l -lactide and trimethylene carbonate was tested yielding satisfactory to excellent amount of polymeric material with Mn ∼ 15–70 kg/mol for e-caprolactone, and ∼30 kg/mol for trimethylene carbonate with good degree of control over the molar mass distribution, initiation efficiency. An excellent conversion of l -lactide to methyl (S,S)-O-lactyllactate is observed upon catalysis by one of the complexes at room temperature.

The reactivity of cyclopentadienyl and indenyl molybdenum(II) complexes [(η5-Cp′)Mo(CO)2(NCMe)2][BF4] (Cp′ = Cp, Ind, 1,3-Ph2C9H5) with a series of planar N,N,N-chelating ligands was scrutinized. The planar N,N,N-chelating ligands give κ2-complexes [(η5-Cp′)Mo(CO)2(κ2-N,N,NL)][BF4] those undergo in particular cases a spontaneous release of carbon monoxide to give [(η5-Cp′)Mo(CO)(κ3-N,N,NL)][BF4] depending on several factors including the basicity of the tridentate ligand as well as the nature of the starting molybdenum(II) compound. This behaviour strongly contrasts with tripodal ligands those do not affect cis-Mo(CO)2 moiety even upon tridentate coordination. All structure types, discussed in this work, were elucidated by the spectroscopic measurements as well as by the X-ray crystallography.