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The reactivity of κ2‐N,S‐chelated ruthenium borate complexes, [Ru(PPh3)(κ2‐N,S‐(NC7H4S2)Ru{κ3‐H,S,S′‐H2B (NC7H4S2)2}] (1 a) and [Ru(PPh3)(κ2‐N,S‐(NC5H4S){κ3‐H,S,S′‐H2B(NC5H4S)2}] (1 b) with monoboranes have been explored. The prolonged room temperature reaction of [Ru(PPh3){κ2‐N,S‐(NC7H4S2)}{κ3‐H,S,S′‐H2B(NC7H4S2)2}], 1 a with an excess of [BH3 ⋅ THF] led to the formation of hydrogen‐rich complex, arachno‐[PPh3(κ2‐B3H8)Ru{κ3‐H,S,S′‐H2B(NC7H4S2)2] (2). In a similar fashion, the isomeric ruthenatetraborane complexes of [Ru(PPh3)(κ2‐N,S‐(B3H8){κ3‐H,S,S′‐H2B(NC5H4S)2}], 4 and 5 were isolated from the room temperature reaction of 1 b with [BH3 ⋅ THF]. In complex 2, the borate ligand, [H2B(NC5H4S)2] and the PPh3 occupy the endo and exo sites of the butterfly‐shaped RuB3 core, respectively. In contrast, the borate unit [H2B(NC5H4S)2] in 4 sits on the exo position of the butterfly core, while the phosphine ligand occupies the endo site. Multinuclear spectroscopic analyses were done to characterize all new complexes and the structures were further confirmed by single‐crystal X‐ray diffraction analysis. Density functional theory (DFT) calculations were performed to probe into the bonding modes of these complexes. [ABSTRACT FROM AUTHOR]

A series of triborane and tetraborane analogues have been isolated and structurally characterized utilizing chalcogenatoborate ligands Li[BH3(EPh)] (E=S or Se). Thermolysis of [Cp*TaCl4] in the presence of Li[BH3(SPh)] afforded bimetallic tantallaheteroborane [(Cp*Ta)2(μ‐η3:η3‐B2H4S)(μ‐η2:η2‐SBH3)] (1) and hexasulfido trimetallic complex [(Cp*Ta)3(μ‐S)4(μ‐SPh)2] (2). Compound 1 is a fused ditantallaheteroborane, in which both di‐ and triborane analogues are stabilized by two tantalum atoms. In an attempt to synthesize the selenium analogues of 1 and 2, room‐temperature reaction of [Cp*TaCl4] with Li[BH3(SePh)] was carried out, which afforded bimetallic tantallaheteroborane [(Cp*Ta)2{μ‐η3:η3‐B3H6(SePh)}{μ‐SePh}2] (3), monometallic tantallaheteroboranes [Cp*Ta(SePh)2{B4H8‐n(SePh)n}] (4: n=0, 5: n=1), and trimetallic species [(Cp*Ta)3(μ‐Se)4{μ‐Se2(Se)}] (6). Compound 3 is the rarest example of triborane analogue {B3H6(SePh)} in the coordination sphere of two tantalum atoms. Whereas compounds 4 and 5 are examples of unsaturated metallaheteroboranes, in which the tetraborane analogues are stabilized in the coordination sphere of tantalum. One of the unique features of 3 and 5 is the presence of terminal B‐SePh. Compound 6 has similar Ta3Se6 trisbutterfly core as that of 2 with additional bridging selenide unit. All the compounds have been characterized by NMR spectroscopy, mass spectrometry, IR spectroscopy and single‐crystal X‐ray diffraction studies. [ABSTRACT FROM AUTHOR]

Building upon our earlier studies of cobaltaheteroboranes, we explore the chemistry with heavier group 9 metals. Reaction of [Cp*M(µ‐Cl)Clx]2 (Cp* = η5‐C5Me5; M = Co, x = 0; M = Rh or Ir, x = 1) with [LiBH4·THF], followed by thermolysis with an excess of chalcogen powders (S or Se), affords dimetallaheteroboranes nido‐[(Cp*M)2B2H2E2], 1–4 (1: E = S; 2: E = Se, M = Co; 3 and 4: E = Se, M = Rh and Ir, respectively) in moderate‐to‐good yields. The solid‐state structures of these compounds show open‐cage triple‐decker clusters. Attempts to isolate the Te analogue have failed; however, in the case of cobalt, we have isolated an 11 skeletal‐electron‐pair nido‐[(Cp*Co)2B5H5Te2], 5. The X‐ray diffraction structure of 5 shows monocapped square antiprismatic geometry, with two Te atoms in the core. To close the central four‐membered B2E2 open ring of nido‐1 and nido‐2, we have performed a reaction with [Ru3(CO)12], which leads to the formation of closo‐[(Cp*Co){µ‐η5:η5‐B2H2E2M}M{µ‐Ru(CO)4}], 6 and 7 [6: E = S; 7: E = Se; M = Ru(CO)2]. In contrast, the reactions of nido‐2 and nido‐3 with [Fe2(CO)9] result in heterometallic clusters nido‐[(Cp*M)Fe(CO)3B2H2Se2], 8 and 9 (8: M = Co; 9: M = Rh), [(Cp*Co)Fe3(CO)8Se2], 10, and [(Cp*Co)Fe2(CO)7Se], 11. As nido‐8 also contains a four‐membered open ring B2Se2, we have treated this with [Ru3(CO)12], which yields closo‐[(Cp*Co){µ‐η5:η5‐B2H2Se2M}M{µ‐Fe(CO)4}], 12 [M = Ru(CO)2], which is analogous to that of 7. In addition, we have analyzed the divergence in the reactivity of nido‐[(Cp*M)2B2H2E2], 2–4, with the help of density functional theory calculations. [ABSTRACT FROM AUTHOR]

The quadruply bridged bimetallic dithiolato complex [(Cp*W)2(µ-S)2(µ,η2-S2CH2)] (3) and the open-cage triple-decker complex [(Cp*W)2(µ-S)(µ-η4:η4-B2H2S2)] (2) have been prepared by treatment of CS2 with in situ generated [(Cp*W)2(B2H6)2] (1) obtained by the reaction of [Cp*WCl4] with [LiBH4·thf]. The solid-state X-ray diffraction structures of these complexes show the presence of doubly bridging η2-S2B2H2 and η2-S2CH2 ligands with a short W–W bond. While many dimolybdenum–sulfur compounds are known, examples of the tungsten–dithilato complexes are relatively few, and in this respect, the isolation of [(Cp*W)2(µ-S)2(µ,η2-S2CH2)] represents a rare example of this type. Electronic-structure analysis, on the grounds of density functional theory (DFT), together with X-ray diffraction studies, has rationalized the presence of short W–W and B–B bonds. Large HOMO–LUMO gaps have been observed for both compounds, which is consistent with their thermodynamic stability. All of the compounds have been characterized by mass spectrometry, IR spectroscopy, and 1H NMR, 11B NMR, and 13C NMR spectroscopy in solution, and the structural architectures have been unambiguously established by X-ray diffraction crystallographic analysis. [ABSTRACT FROM AUTHOR]

Several early-late heterodimetallaborane clusters have been isolated and structurally characterized through spectroscopic and crystallographic analysis. The thermolysis of [Cp2Zr(BH4)2] (Cp = η5-C5H5) with [Cp*IrB3H9] (Cp* = η5-C5Me5) and [(Cp*Rh)2B2H6] yielded arachno-[(Cp2Zr)(Cp*Ir)B3H9] ( 2) and arachno-[(Cp2Zr)(Cp*Rh)B4H10] ( 4), respectively. In a similar fashion, the reaction of [Cp2Hf(BH4)2] was performed with the same set of group 9 metallaboranes that led to the formation of arachno-[(Cp2Hf)(Cp*M′)B4H10] ( 5: M′ = Ir; 6: M′ = Rh). To the best of our knowledge, 2 is the first structurally characterized pentaborane(11) analogue containing zirconium, while the clusters 5 and 6 are the first examples with Hf in a hexaborane(12) core. The bonding between the Zr atoms and the boron ring was studied computationally by DFT methods, and 2 can be defined as a dimetallic analogue of arachno-B5H11 on the basis of the combined experimental and computational results. [ABSTRACT FROM AUTHOR]

Treatment of [Cp*TaCl SB 4 sb ] with chalcogen-ligated monoborate nucleophiles, [BH SB 3 sb (EPh)] SP - sp (E = S or Se) yielded various smaller borane analogues. Cover Feature: Metal Coordinated Tri- and Tetraborane Analogues (Eur. J. Inorg. Keywords: Boranes; Chalcogens; Metallaheteroboranes; Tantalum; Structure elucidation EN Boranes Chalcogens Metallaheteroboranes Tantalum Structure elucidation 4407 4407 1 11/24/21 20211122 NES 211122 B The Cover Feature b shows triborane and tetraborane analogues which are stabilized in the coordination sphere of tantalum atom(s). [Extracted from the article]